How do you define a "trilogy"? Is it a series of three connected stories? One big story told in three parts? What if you have a series with more than three films? Can three of them be plucked out of the sequence and considered a trilogy?

In this case, we're accepting all of the above in our definition of film trilogy. What we're not considering are movies that are linked only thematically. Screen Rant loves us some "Cornetto" trilogy, aka the films of Edgar Wright starring Simon Pegg and Nick Frost, but strictly speaking, Cornetto isn't a trilogy — it doesn't share any common characters, settings, or plots.

A genuine trilogy can be constructed in different ways. In its purest form, a trilogy is planned from the outset as a three-part story. It starts with the first movie, which is an introduction to the world and its characters and overall scenario. It continues with numerous plot complications and heavier drama in the second part. The finale wraps up the entire saga with an ending that remembers everything that came before. That said, there are also excellent trilogies where a solo flick was so successful that its filmmakers decided to add two more films to continue and finish the tale.

To create our definitive list of the top 15 trilogies in cinematic history, we carefully considered a variety of factors, such as quality, reception, lasting influence on cinema and/or pop culture, and the actual scores a movie was assigned by both critics and general audiences. With that in mind, here's Screen Rant's take on The Best Movies Trilogies Of All Time.

15. The Matrix

Keanu Reeves as Neo in The Matrix Revolutions

The Matrix took movie screens by storm in 1999 and redefined modern cinema overnight. Using its own filmmaking language and techniques, its virtual world showed us so many things we'd never seen before (many of them based on anime's tendency to defy the laws of physics) while wrapped around a story filled with heady philosophical ideas and astounding action sequences. It didn't hurt that it reframed the perennial "Hero's Journey" — the same basic story structure used by Star Wars and countless others — as something fresh, smart, and stunning to behold.

Its sequels were another case of the "couldn't live up to the original" problem that plagues so many franchises, though it's hard to pinpoint exactly what went wrong. It certainly wasn't the ideas department, as the Wachowskis brought a truckload of fascinating new ones to the table. The production design, visual effects, and overall ambition took gigantic leaps forward, while intriguing new characters were added to the already appealing cast.

But something fell apart somewhere in the presentation. A precisely-defined endpoint was set forth in the original: Morpheus (Laurence Fishburne) told Neo (Keanu Reeves) that "as long as the Matrix exists, mankind will never be free." In other words, it was Neo's destiny to destroy the Matrix and free all the humans trapped inside. The sequels — the stylish-but-bloated The Matrix Reloaded and the dour, unsatisfying The Matrix Revolutions (both released in 2003) — ignored this mandate entirely, instead deciding that saving the Matrix was preferable. As long as über-powerful Agent Smith (Hugo Weaving) was ejected from the system, Neo and the gang would settle for peaceful coexistence with the machines (as long as humans still in the Matrix could opt-out of it, or... something). Because nothing could possibly go wrong with that.

The change was undoubtedly so that Warner Bros. didn't have to close the door forever on one of its most profitable franchises. (For years, rumors have circulated that more Matrix movies are being considered.) Yet if "everything that has a beginning has an end," as The Matrix Revolutions told us, it's a crying shame — not to mention confusing — that this trilogy was robbed of its proper conclusion. Nevertheless, the transformative experience of The Matrix makes this an unmissable slice of pop culture history.

14. Iron Man

Robert Downey Jr. in Marvel's Iron Man

What can be said about the first Iron Man that hasn't already been stated many times over? It launched both Marvel Studios and the connected "Marvel Cinematic Universe." It jumpstarted Robert Downey Jr.'s career, elevating him to the highest-paid actor in Hollywood. The movie benefited strongly from the catharsis of seeing Downey overcome his own history and settle into a high-profile role that was the perfect showcase for his comedic and dramatic skills. The cast created most of its own dialogue in that first movie, which added to its realism and sharp humor, while director Jon Favreau staged several stand-up-and-cheer action scenes that audiences couldn't get enough of.

Iron Man 2 stumbled after being rushed into production after the first movie's box office success, jamming in far too much story for a single film. The over-complicated plot throws a number of obstacles in Tony Stark's path: an enemy with a personal vendetta against the Stark family, a business rival who wants to take Tony down, the U.S. government wanting to acquire the Iron Man technology for its own uses, and the slow poisoning of Tony's body by the arc reactor that's made him a superstar. It also tries hard to work in a romantic subplot with Gwyneth Paltrow's Pepper Potts, even though that bit feels tacked-on. But hey, it also gives us that cool suitcase armor, and introduces Scarlett Johansson's Black Widow in a flashy fight scene.

Iron Man 3 picked up the story strands of The Avengers while bringing in director Shane Black to craft a grittier story about yet another figure from Tony's checkered past who returns to haunt him. The tone and presentation of the film is drastically different than what came before, digging deeper into Tony Stark's soul and finally letting him find peace in both his personal and superhero lives. It also featured a truckload of thirty-some Iron Man suits, all of which show up for the finale.

Although this trilogy has been overshadowed by other Marvel films, Iron Man's golden face plate remains the icon that defines the entire enterprise. Robert Downey Jr., meanwhile, continues to change and grow his portrayal of Tony Stark; his recent turn in Captain America: Civil War may have been his best yet.

13. Spider-Man

Tobey Maguire as Peter Parker in Spider-Man 2

Peter Parker is Marvel Comics' most popular character, a hero with enduring appeal who's been around almost as long as DC rivals like Superman and Batman. Encouraged by Bryan Singer's success with the X-Men movies, Sony decided to revive its long-dormant film rights to Spider-Man. This was a character who'd never been given his proper due, after all, having suffered through a cheesy live-action TV show, and a handful of cartoons that ranged from halfway decent to downright goofy. Getting to see a proper translation of Marvel's wall-crawling hero with modern effects and filming techniques sounded brilliant.

For years, it looked like James Cameron was going to take on his first superhero flick, but those plans fell apart. When Sam Raimi was handed the reigns to create a big-budget Spider-Man movie for Sony, Marvel fans were a little skeptical. Viewers of the Evil Dead movies, however, were wholeheartedly on board, knowing exactly what Raimi was capable of. The director surprised everyone by casting indie darling Tobey Maguire, who showed off an astonishingly buff physique at the movie's first press conference. Fans' fears were fully erased when the trailers arrived, showing off an exciting blend of strong storytelling, colorful comic-like production values, and dynamic, fast-paced visuals that brought Peter's spider-powers into the real world.

Spider-Man swung into theaters in 2002, solidifying a new age of superhero films that has only increased in dominance since. Raimi gave us a near-perfect depiction of the classic story of the everyman who gains extraordinary powers, and Maguire proved himself perfectly cast as the good-hearted hero who's forced to learn harsh lessons. Spider-Man 2 ignored the Batman formula of focusing on the bad guys, instead furthering the growth and change of Peter Parker as he matured into his role as Spider-Man. Sure, it was a bit heavy-handed in continually beating down a down-on-his-luck Peter, but the story — about confidence, purpose, and selfless love — was electrifying, and Alfred Molena gave us a fleshed-out villain in Doc Ock. It bested the first movie in every way.

Spider-Man 3 succumbed to the Curse of the Third Film, as Raimi acquiesced to studio and fan pressure to include fan-favorite villain Venom, while the director himself preferred classic baddie Sandman. It also featured an unwelcome retcon regarding Uncle Ben's murderer, and dangled before us a "happily ever after" for Peter and MJ before tossing that whole-hog out the window. Going back to the "MJ's been captured" well for a third time for its final fight only made it seem like Raimi was running out of ideas. Add in the culmination of Harry Osborn's story, and it's obvious that Spider-Man 3 tried to do way too much.

A fourth movie was planned but abandoned when Sam Raimi and the studio wanted different things. Andrew Garfield eagerly stepped into the tights for a pair of rebooted films, but despite a fine showing from him, the second movie was a muddled mess. Sony eventually caved to Marvel's superiority in the superhero genre by allowing Marvel to produce a new series of Spidey flicks starring Tom Holland — who exists in the Marvel Cinematic Universe.

12. Evil Dead

Bruce Campbell as Ash Williams brandishing a chainsaw in The Evil Dead II

When childhood friends Sam Raimi and Bruce Campbell decided to make a movie, they had no idea what they were getting themselves into. With Raimi writing and directing, Campbell starring, a location shoot at an abandoned cabin in the Tennessee forest, and a meager budget, on came the rise of The Evil Dead. It's considered among the greatest horror films of all time, because it broke the horror mold by melding it with comedic elements. It had so many horror tropes — a cabin in the woods, an Indian burial ground, incantations from a mystical book, co-stars that turn evil, a hero that barely survives — but it remixed them with witty one-liners and slapstick physical humor. One rave review later (from a certain horror writer in Maine) and there was a phenomenon at the cineplex worth talking about and taking your friends to.

Evil Dead II picks up immediately where the first movie left off, finding Campbell's Ash Williams unable to escape the cabin where he's just lost all of his friends. Although the movie retreads much of the same ground as the first, it does so with a larger budget and far more confidence. It's in this episode that Ash is forced to cut off his own hand (it becomes possessed) — a twist that ultimately leads to his adoption of the iconic "chainsaw hand."

The final entry abandons the naming convention used thus far, going with Army of Darkness. It picks up Ash's story after he's been sucked through a portal and deposited in medieval times, where he leads an entire kingdom against an invasion of the dead. Some of the darker edge is lost in this one, but the snark is dialed up to eleven, as is the scale.

Campbell practically invented the "cocky hero" archetype, swaggering his way through the series and into the heart of pop culture itself. Raimi would find this platform a perfect launchpad into a successful, diverse film career. Campbell would return as Ash Williams 22 years later in the TV show Ash vs. Evil Dead on the Starz network.

11. The Before Trilogy

Céline and Jesse touching foreheads in Before Sunrise.

No heroes. No villains. No explosions or enormous stakes. Before Sunrise is a quiet little movie about a chance encounter between two lost souls that leads to an unlikely romance. Unapologetically tender, subtly sexy, yet never descending into sap, it reeled in audiences with an irresistible pair of travelers who agree to wander Vienna all night, talking and exploring the city, while waiting for their respective journeys to continue in the morning. Ethan Hawke and Julie Delpy demonstrate unquestionable on-screen chemistry, while flirting and revealing the deepest secrets they hold — because they can't tell them to friends and loved ones. Over the course of a single night, these two strangers come to know one another in the most intimate of ways... And then part company.

Before Sunset revisits them nine years later, when Celine (Delpy) finds Jesse (Hawke) at a Parisian bookstore, where he's signing his own bestseller for customers. Jesse has to get to the airport after the signing, but he has an hour to spend with Celine, during which they delve into even more personal topics. This time, they decide to act on their feelings and wind up together.

Before Midnight has a completely different tone, picking up another nine years on, this time with our couple now married (with twin daughters), but feeling romance slipping away in the mundane of day-to-day life. Given how much audiences have invested in these two by this point, you can imagine how it ends. But that's not really the point.

What the "Before" trilogy did was show us that great cinema doesn't have to be filled with wall-to-wall plot. This humble trio of "movies about people talking," often in long, single takes, was every bit as absorbing as the greatest moments that film has ever recorded. Also setting this trilogy apart is the fact that its two stars wrote or rewrote most of the dialogue from all three movies, which is at least part of the reason the movie feels so natural and real. Writer/director Richard Linklater has given the theater plenty of great movies, but the Before trilogy stands alone as an exquisite work of art.

10. Mad Max

Mel Gibson in Mad Max 2 The Road Warrior

Before Katniss Everdeen, Caesar the ape, or Neo, before even Sarah Connor or Snake Plissken, and long before post-apocalyptic dystopian drama was all the rage... George Miller gave us Max.

In 1979, Mad Max introduced cinephiles to Max Rockatansky (Mel Gibson, in his first major role), an ex-cop and a wanderer across the wastelands of Australia after society has collapsed and resources become dangerously scarce. He's a skilled driver and an adept warrior who can't seem to stop helping others despite his desire to be alone after his wife and son are murdered. The first film is essentially a revenge thriller wrapped in action movie trappings, but Miller somehow manages to turn the dry, dull landscape of the Australia desert into a gripping, stylish backdrop for life after the end of the world.

Two years later, Max returned in The Road Warrior, which added a mythological aspect to the character. The story is propelled by Max's need to procure coveted gas to power his signature hotrod, but eventually it brings him into the orbit of a group of survivors trying to defend themselves against a wicked gang led by "Lord Humungus." You can guess what happens next.

The franchise took four years off before returning for Gibson's final (and what Miller thought would be his final) entry, Mad Max Beyond Thunderdome. A bigger, more expansive film, this one incorporates the familiar theme of survival-vs.-morality as Max goes up against an anti-villain played by Tina Turner (sporting what may be the most extreme shoulder pads of all time) to save another colony of refugees and help them find a new home.

Defined by bizarre characters with goofy names, over-the-top action set pieces, and a reluctant hero always forced to make difficult choices, the Mad Max franchise maintained a high standard of quality throughout its run. Thirty years after Thunderdome, George Miller triumphantly revived the franchise with the universally-adored Mad Max: Fury Road. Tom Hardy took over the titular role (he's contracted for up to four more, should Miller choose to go that far), and Miller dove back into Max's world with a renewed vigor and sense of purpose. He's currently at work on the next film in the series.

9. The "Three Colors" trilogy

Irene Jacob and Jean-Louis Trintignant in Red

Don't feel bad if you've never heard of this one. It's an art house trilogy by one of the most acclaimed European directors of all time — who you also may have never heard of. Krzysztof Kieslowski constructed this intricate house of cards, released in 1993 and 1994, with subversive twists on France's political ideals: liberty, equality, and fraternity. Each movie stars a different cast, but is interconnected in a shared continuity in subtle and surprising ways. Blue is considered an "anti-tragedy" themed around liberty; White is an "anti-comedy" on the theme of equality; Red is an "anti-romance" about fraternity. And each works their respective color into the scenery in clever ways.

Juliette Binoche stars in Blue, a study on emotional liberty, as a widow in mourning for her recently deceased husband and daughter. Instead of remembering them, she goes to extremes to distance herself from her pain. Julie, the main character, tries to withdraw from society and live in isolation, but is drawn back in when she discovers that her late husband had a mistress.

In White, Zbigniew Zamachowski is Karol, a man who's subjected to a humiliating divorce, loses everything, and is reduced to a street beggar. A chance encounter opens his eyes to an opportunity to turn the tables on his ex. It highlights equality in the most unexpected of ways: a sad, lost soul who turns to vengeance to balance the scales of justice. His success is equal parts cathartic and tragic, a tale of revenge served incredibly cold that has a more profound impact on Karol than it does his victims.

Red is the most acclaimed of the trilogy, in which Kieslowski looks at the meaning of fraternity by presenting a group of characters with nothing in common whose lives become entwined. The core of the story has young Valentine (Irene Jacob) encounter a reclusive, sullen retired judge named Kern (Jean-Louis Trintignant). Despite his glum personality and detached behavior, Valentine continually finds herself visiting him, trying to uncover the humanity he's worked so hard to hide. There's much more to it of course, and the finale assembles Kieslowski's jigsaw puzzle together in poetic fashion.

8. Back to the Future

Christopher Lloyd and Michael J. Fox in Back to the Future

Narratively speaking, Back to the Future is a perfect movie. Every line of dialogue and plot point matters, every conflict introduced is resolved in a pulse-pounding, brilliantly tidy way. It creates rules of time travel that rely on a MacGuffin (either the DeLorean or the Flux Capacitor, take your pick), yet those rules make logical sense and the movie never violates them. Amazingly, Back to the Future does a remarkable amount of world-building without putting the whole world in jeopardy; it's a story that revolves entirely around the lives of one family.

Who didn't thrill to the story of Marty McFly (Michael J. Fox), wannabe rock star who goes thirty years back in time, saves his parents and transforms his loser family unit into a happy, loving, successful household. He gets the girl (though technically, he never lost her), prevents his best friend from dying, and saves the day. He even invents rock 'n' roll. It was a box office triumph.

Back to the Future Part II had impossibly high expectations to live up to, but its main story arc suffered from a lack of creativity and remake fever (the wholly unnecessary return trip to 1955). On the other hand, time and distance have bestowed Part II's first act with rose-colored glasses, as all of its ideas about the future have embedded themselves permanently into our everyday vernacular: hoverboards, wearable technology, flatscreen televisions, smart homes, tablet computers, and much more.

Part III injected more originality into the mix, taking our heroes back to the Old West and relying less on repeating the same old story beats. It culminated with a finale set aboard a runaway train that managed to up the intensity over the first film's stormy showdown, not to mention introducing a love interest for Doc Brown (Christopher Lloyd). Neither sequel quite lived up to the first film's jolt of crisp storytelling or justified turning a truly fantastic film into a good-not-great trilogy.

But there's no denying that Back to the Future is one of the greatest adventures ever put on film.

7. Captain America

Chris Evans as Steve Rogers in Captain America: Civil War

Captain America: The First Avenger introduces us to Steve Rogers (Chris Evans), a pure-hearted American who wants to serve his country in World War II. But Rogers is a weakling with no strength and no skills to speak of, aside from a keen tactical mind and an unerringly straight moral compass. When he's injected with a super-soldier serum, he becomes Captain America, the country's first superhero and a central figure in defeating the Nazis.

It also introduces us to Steve's best friend, "Bucky" Barnes (Sebastian Stan), who is presumed dead in the second Great War after falling from an impossible-to-survive height. Bucky nevertheless returns in the modern day in Captain America: The Winter Soldier, much like Steve, who'd been frozen in ice beneath the Atlantic during First Avenger's final battle. Bucky, it's explained, was saved and abducted by Hydra, and brainwashed into the titular consummate assassin, complete with a metal arm and mad wetwork skills. While Steve wrestles to put a corrupt S.H.I.E.L.D. out of business, Bucky is used as a tool of his enemies, but Cap finally manages to get through to him before the movie's end.

Captain America: Civil War, the conclusion of the trilogy, would have been such an easy misfire. Focusing on the comics' story of the same name, it presents the Avengers — and their leader, Captain America — with an ultimatum about superheroes falling under the supervision of world governments. It also features a major conflict between Cap and Iron Man. And it's no small miracle that it manages to do right by a dozen major characters — including introducing Black Panther (Chadwick Boseman) and the new Spider-Man (Tom Holland). But filmmakers Joe and Anthony Russo wisely keep the story's heart entrenched in the bromance between Steve and Bucky, now reformed but still capable of being "activated" as the Winter Soldier with the proper sequence of phrases. This allows Steve's relentless pursuit of saving his friend to form the through-line for the entire trilogy, showing that Cap would go so far as defying the law if it meant helping his oldest pal. As superhero movies go — not to mention an integral part of Marvel Studios' connected universe — that's some profoundly emotional stuff.

The Captain America films may not be three parts of one story, but their characters forge an emotional journey that viewers can easily track from one flick to the next. It also accomplishes the unprecedented task of besting itself with each subsequent entry. (How many other trilogies can you think of where the third movie is the best of the series?)

When it comes to the Marvel Cinematic Universe, Iron Man may get all the attention, but Captain America is the crown jewel.

6. Indiana Jones

Harrison Ford as Indiana Jones in Raiders of the Lost Ark

You may be tempted to think of George Lucas as a one hit wonder. Sure, he had a few smaller successes here and there — American Graffiti, Willow — but aside from a galaxy far, far away, his career hasn't exactly been filled with beloved classics. Radioland Murders wasn't awful. Red Tails should have been better. Strange Magic? Uninspired. And the less said about Howard the Duck, the better.

But there is that other franchise that Lucas is known for, the one he teamed with BFF Steven Spielberg on. Once again drawing on his love of matinee serials, Lucas dreamed up a swashbuckling archaeologist named Indiana Jones, a bookish professor who becomes a rough-and-tumble adventurer when some ancient treasure caught his attention. The fact that his exploits often brought him into conflict with forces of evil, such as Nazis, was almost coincidental; he never set out to be a hero. But his world-weary determination, rascally charm, uncanny knack for survival, and wry sense of humor always kept us coming back for more.

His first outing, Raiders of the Lost Ark, was a near-perfect movie in every way. Spielberg's kinetic direction brings Lucas' vision to life with spontaneity and excitement, while Lucas' plot centers on one of the most sought-after relics of all time. Their concoction was the role Harrison Ford was born to play, despite not being Lucas or Spielberg's first choice. Indy was surrounded with colorful, mustache-twirling villains and a beautiful, strong-willed woman (Karen Allen, who was anything but a damsel). With his fedora, leather jacket, and bullwhip in hand, a new kind of movie hero was born, and he's one that's lasted through multiple generations.

Indiana Jones and the Temple of Doom begins with a thrilling action sequence set in a Shanghai nightclub, followed by a daring escape from a crashing airplane. When Indy, his sidekick Short Round (Jonathan Ke Quan), and hilariously exasperated new love interest Willie Scott (Kate Capshaw), arrive at Pankot Palace, they discover the terrifying temple of the Thuggee cult, who make ritual human sacrifices and enslave children. For a good thirty to forty-five minutes, the movie descends into an oppressively bleak look at an evil-worshipping cult. Thankfully, things pick up again before the end, culminating with an unforgettably thrilling mine cart chase.

Indiana Jones and the Last Crusade restored the lighthearted feel of the first film, sending Indy on a quest — aided by his father (a cheeky Sean Connery in one of his best performances), no less — to find the Holy Grail. Those dastardly Nazis reared their ugly heads again, there were sensational chases through Venetian canals and Jordanian deserts, and this time there were two Dr. Joneses to save the day.

We've chosen not to include Indiana Jones and the Kingdom of the Crystal Skull, as the first three movies form a winning "original trilogy" a la Star Wars. Besides, Crystal Skull is a "19 years later" sequel that lost the plot by following the rabbit trail of Indy's long-lost son (Shia LaBeouf) — a storyline Lucas stubbornly insisted on pursuing, even though it never works. With Lucasfilm now in Disney's hands (and Lucas himself out of the picture), plans are in motion for a fifth Indiana Jones film, which will hopefully wash away the meh taste left by number four.

5. The Dark Knight Trilogy

Christian Bale as Batman in The Dark Knight

When Christopher Nolan was handed the keys to the Batmobile, he knew that the only way he could make a superhero movie was to do it as realistically as possible. That meant he had to approach the Batman mythos as if it were something that could truly happen. No superpowers, no fantasy or science fiction, no standard comic book stuff. It would be drama that rang true, performed by serious actors, almost literary in quality.

To truly appreciate the achievement that was Batman Begins, you have to remember the Bat-flick that came before it: the abysmal Batman & Robin. Nolan's instinct was to get as far away from that silly, hyper-colorful fantasy as possible by grounding his movie in the real world. One of the smartest ways he did that was to avoid lazily relying on CGI visual effects, instead staging enormous, elaborate sequences with real objects, such as the amazing tractor trailer that flips end-over-end in The Dark Knight or the mid-air jailbreak that opens The Dark Knight Rises. Nolan is also singlehandedly responsible for bringing IMAX cameras to blockbuster movie-making, leading to the format's adoption by other filmmakers and an exponential rise in its popularity.

But none of these things would matter if the Dark Knight Trilogy wasn't a master class in cinematic storytelling. Or if Nolan hadn't cast high-pedigree actors like Christian Bale, Gary Oldman, Morgan Freeman, Michael Caine, and a bravura turn by the late Heath Ledger as a different kind of Joker, among others. The high point is inarguably The Dark Knight, which is widely regarded as the finest superhero movie ever made.

Unlike other superhero sagas, the Dark Knight Trilogy boasts genuine, bonafide closure. We got to see Batman Begin, after all, so why shouldn't we witness his end? Nolan must've felt the same way, as he gave his hero and his trilogy a definitive conclusion.

4. The Godfather

Al Pacino and Marlon Brando in The Godfather

It should come as no surprise that the celebrated saga of the Corleone mafia crime family ranks highly on our list. The first two films in particular are treasured classics for a myriad of reasons. It defined the careers of director Francis Ford Coppola, stars Marlon Brando and Al Pacino, and novelist and screenwriter Mario Puzo. It won a total of nine Academy Awards, including Best Picture for the first and second films.

A moody, fully-realized world is introduced in the soft lenses and mud-colored cinematography of The Godfather. The film told the story of Michael Corleone (Pacino), a World War II veteran who returns home to his Italian-American family in New York and becomes deeply embroiled in the mafia war his father is waging. At its barest of bones, the first film is a tragedy about a good man who goes bad, albeit in part as a result of the circumstances around him. It ends with the death of his father Vito (Brando), and Michael taking his place as the head of the Corleone family.

The Godfather Part II, the first sequel to ever win Best Picture, continued Michael's story as Don Corleone, charting his schemes and sins to come out on top over rival crime families. Robert de Niro appeared in flashback scenes as a young Vito Corleone, depicting the patriarch's rise from Sicilian orphan to mob boss. Pacino's nuanced performance in Part II is considered one of the best of all time, and the movie became the rare example of a sequel that's as cherished as its progenitor.

While two years separated the first two movies, Part III came after a 16-year gap, which may explain why it never achieved the same success as the first two. Coppola designed the finale as the "epilogue" of Michael's story (which he believed was complete after Part II), with an aging Michael Corleone trying to atone for his sins while appointing a successor (Andy Garcia).

The first movie is one of the most quoted films of all time, even though it's brimming with stereotypes. The genius of the Godfather saga is how masterfully it weaves those very cliches into a tapestry so compelling, you can't take your eyes off of it.

3. Toy Story

Woody, Buzz and the gang in Pixar's Toy Story 3

It's the best-reviewed trilogy of all time. Rotten Tomatoes shows that critics adored all three movies across-the-board. Only the second film scored less than 100% approval, instead landing 99% of critics' adoration. (Which can only mean that one critic somewhere out there had a migraine on review day.)

The first movie was a perfect confluence of circumstances. In Toy Story, Pixar changed animation forever by showing the world that computers could produce imagery every bit as expressive and alive as traditional hand-drawn animation -- if not more so. John Lasseter and his cohorts created the first-ever feature-length CGI movie and wowed the world. Technical achievements aside, Toy Story succeeded because it's an ingenious story, at once both original and timeless. Lasseter filled it with timeless characters and archetypes anyone can identify with. The stalwart cowboy hero (Tom Hanks), the delusional space ranger toy who thinks he's real (Tim Allen), the cast of kooky sidekicks, each with a distinct personality. Pixar built a vivid world with its own rules and used it to tell a fable in the classic Disney vein.

Toy Story 2 had Woody discovering he was a valuable collector's item based on an old TV show, forcing him to choose between joining other toys from that same show to live in a museum or returning to the little boy who loved him. It also introduced some great additions to the cast, like cowgirl Jessie (Joan Cusack) and Woody's loyal horse Bullseye. Toy Story 3 was the series' emotional powerhouse, a masterpiece that had Woody, Buzz, and the gang literally staring down their own mortality as Andy grew too old to want to play anymore. The heartbreaking, impossibly beautiful finale was as blissfully perfect an ending as any trilogy could possibly achieve.

A fourth Toy Story is coming, but Pixar has said that it's something completely new and not part of Andy's story, so we believe the first three films still constitute a trilogy. Toy Story 4 will be a love story between Woody and Bo Peep, who fans will remember was "lost" by the time of Toy Story 3.

2. Star Wars: Episodes IV-VI

Mark Hamill as Luke Skywalker in The Empire Strikes Back

There is truly no limit to the influence of the preeminent pop cultural touchstone that is Star Wars. The three original films in the series are undoubtedly the most treasured film trilogy of all time. Did anyone even make movie trilogies before Star Wars came along? Back in 1977, no one could have imagined how Star Wars would change movies, pop culture, and yes even the world, forever. Can you picture a world without Luke Skywalker, Han Solo, or Princess Leia in it? What about Chewbacca? R2-D2 and C-3PO? Yoda? The Jedi, the Force, and lightsabers? The Death Star (er, Stars)? X-Wings?

It's a classic wish-fulfillment fantasy: a young man (Mark Hamill) who's bored with his humdrum life is propelled into a life of adventure, learns he has special abilities, and must rise to the challenge to save the entire galaxy. He meets an old mentor (Alec Guinness) who guides him on his quest, where he makes allies and enemies, discovering a destiny that only he can fulfill along the way. It's a familiar formula that countless stories have drawn upon, but it came at a unique moment in history. In 1977, the Vietnam War was still lingering in Americans' minds. President Nixon was smack in the middle of the Watergate scandal. New York was being terrorized by the Son of Sam murders. The Cold War was heating up, and the entire world was facing an energy crisis. Is it any wonder that this powerfully earnest story format struck a nerve in a cynical world?

The Empire Strikes Back arrived in 1980, wowing moviegoers with a second chapter that took Star Wars to the next level. A bigger budget, a seasoned director, a darker story, and a genuinely shocking revelation about Luke Skywalker's parentage was a perfect formula for a follow-up, and to this day it ranks as the highest-rated entry in the saga. Return of the Jedi wrapped up the story in 1983 by resolving Empire's cliffhanger and destroying both Darth Vader and his Emperor once and for all.

More movies followed, with George Lucas directing a prequel trilogy between 1999 and 2005, which was heavier on visual effects but disappointingly inferior on story and character. More recently, with Disney's acquisition of Lucasfilm, a new trilogy was kicked off, with fans proclaiming it a return to the revered sensibilities of the original trilogy. A series of standalone films set in the Star Wars universe are also in various stages of production.

Add in the full empire of tie-in products and media — books, toys, television, games, music, and so much more — and the full cultural impact of Star Wars may be immeasurable.

1. The Lord of the Rings

Sauron wears the One Ring in The Lord of the Rings

Probably the greatest modern example of a single story told in three parts, The Lord of the Rings is our pick for the best and truest example of a "pure" trilogy. Many have tried to imitate its formula, but nothing can really compete with J.R.R. Tolkien's fantasy saga, retold on the silver screen by director Peter Jackson. There's just no better way to do it than to script, plan, and prep three movies entirely in advance, and then film all at once. The result was a combination of production design, costumes, makeup, cinematography, music, visual effects, acting, and more that enjoyed a consistency so perfect that no other trilogy even comes close.

This achievement can't be overstated. The only other instance on record of an entire trilogy being filmed all at once is Peter Jackson's Tolkien prequel, The Hobbit (which didn't need to be a trilogy at all). James Cameron has stated his plans to film the second, third, and fourth Avatar films all at once, but who knows if that's what will wind up happening.

In 2001's The Fellowship of the Ring, Frodo Baggins (Elijah Wood) is given the sacred mission of carrying the most dangerous object in existence — a golden ring of unprecedented mystical power — into the most evil realm on earth, to the one place it can be destroyed. He's accompanied by a colorful cast of Hobbits, men, a powerful wizard, an elf, and a dwarf. They're dogged at every step by wicked creatures working for the dark lord Sauron, who requires the ring to restore his power and subjugate the world. Kind wizard Gandalf the Grey (Ian McKellen) makes the ultimate sacrifice, while CGI wonder Gollum (Andy Serkis) is glimpsed for the first time.

The fellowship is divided into three groups in The Two Towers (2002), each going in different directions but all working toward the same goal of saving the innocent and defeating Sauron. The pressure was on for Jackson and company to deliver a follow-up that improved on its predecessor — no small feat considering The Two Towers is a story without a beginning or end. A number of major new characters are introduced as we're treated to looks at all new locations in Middle-Earth, along with the exhilarating Battle of Helm's Deep.

The story ended in 2003 with The Return of the King, in which Viggo Mortensen's Aragorn finally embraces his destiny, Frodo and his faithful friend Sam (Sean Astin) succeed in destroying the ring, and Sauron is destroyed. King is a powerhouse punch of emotional impact, providing eye candy on an astonishing scale and paying off every plot thread introduced by the trilogy with beautiful closure for every character.

The Lord of the Rings is essentially a ten-hour movie, and a masterpiece in every sense of the word.

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Did we leave out your favorite movie trilogy? Is The Lord of the Rings the one trilogy to rule them all? Sound off in the comments section.