The movies in the Marvel Cinematic Universe have been mostly praised by critics, but the franchise’s detractors decry the movies’ rigid story structure. While Marvel has entries from wildly different genres, there are commonalities among all the movies: quippy one-liners, a conventional romantic subplot, a one-and-done villain — and a big, spectacular showdown in the third act. The best ones use this battle sequence to explore the trajectory of the character arcs and go out with a bang. The worst ones have a faceless army and no challenge for the heroes. Here are The 5 Best (& 5 Worst) Third-Act Battles In The MCU.

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Best: The Avengers

The Avengers standing together for the first time during the battle of New York

Every good action set piece follows its own three-act story structure, with the stakes established early on, the action rising in the middle section, and everything culminating in a climax. The Battle of New York at the end of 2012’s The Avengers has all of that. Earth’s mightiest heroes unite for the first time as Loki and the Chitauri begin their invasion of the city.

Captain America galvanizes everyone with a battle strategy before Iron Man takes the government’s nuke and sends it through the wormhole, making “the sacrifice play” that Cap said he never would. Plus, midway through the battle, Joss Whedon gave us the cinematic version of a splash page, with a sweeping tracking shot catching up with all the Avengers.

Worst: Avengers: Age of Ultron

The Avengers battle in Sokovia in Avengers: Age of Ultron

While the final battle in the first Avengers movie had technical gusto, unforgettable cinematography, and its own tight internal story structure, the final battle in the second one, Age of Ultron, was pretty messy and inconsistent. Instead of building the action to a breathtaking climax like he did in the first one, Joss Whedon just threw whatever he could think of at the screen to see what would stick.

The action is all over the place, and the stakes never seem that high — we’re just watching CGI robots get destroyed. In the end, Ultron turns out to be underwhelmingly easy to defeat, as the Hulk just beats him up and then Vision destroys his consciousness.

Best: Thor: Ragnarok

Taika Waititi reportedly used “Immigrant Song” as the soundtrack over the sizzle reel that he used to pitch his vision for Thor: Ragnarok to Marvel. So it’s fitting that the iconic Led Zeppelin track — which uses a ton of imagery from Norse mythology in its lyrics — plays over the final battle.

Just when Thor has given up hope, having lost his eye and been outmatched by Hela, he has a vision in which his father Odin reminds him that he doesn’t get his power from a hammer; he gets it from within. In a crash of thunder, Thor bursts onto the Bifrost Bridge to blaze his way through Hela’s armies. It’s glorious.

Worst: Iron Man 3

Legion of Suits in Iron Man 3

Shane Black’s Iron Man 3 gets off to a promising start, but it quickly goes off the rails in its second act. This was mainly a result of then-Marvel chief Ike Perlmutter nixing a female villain from the script and forcing Black to make Aldrich Killian the primary antagonist.

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This resulted in a third-act battle in which a guy whose elevator pitch was ignored by Tony Stark 20 years ago kidnaps the President of the United States in an overly convoluted attempt to get back at Tony. When the Iron Legion shows up to take care of everything, Tony becomes basically redundant. This battle sequence is a mess.

Best: Guardians of the Galaxy Vol. 2

Ego and Peter clash in Guardians of the Galaxy Vol 2

In Guardians of the Galaxy Vol. 2, Peter Quill finds out his dad is a genocidal planet, aptly named Ego, who wants to remake the universe in his own image. All of the movie’s conflicts converge as Gamora and Nebula learn Ego’s secret, Yondu arrives to save his adopted son from his evil biological father, and the Sovereign’s fleet returns for round two.

James Gunn has always nailed the balance of humor and emotion in the Guardians movies, and this is no different. From Rocket and Groot’s hilarious back-and-forth with the detonator to Quill saying, “You shouldn’t have killed my mom and squished my Walkman,” set to Fleetwood Mac’s “The Chain,” this is a terrific battle sequence.

Worst: Captain Marvel

Captain Marvel Origin Costume

Captain Marvel nicely subverted the MCU’s formula for origin stories. Unfortunately, its final battle lets it down. It never feels like Carol Danvers is in any danger throughout the entire sequence. She just spends the battle discovering convenient new powers that can incapacitate the bad guys, like the ability to punch spaceships out of the sky.

With Yon-Rogg confronting Carol, and Ronan the Accuser bringing his forces to Earth, the stakes should be high at the end of Captain Marvel. But it never feels that way, because the villains are hopelessly outmatched by Carol and the full extent of her powers.

Best: Captain America: Civil War

Bucky and Cap fight Iron Man in Civil War

The final battle in Captain America: Civil War doesn’t involve spaceships blowing each other up or skyscrapers crashing to the ground. It just involves three guys fighting it out. But the stakes are higher here than in most city-flattening battles. Right after Tony Stark calls a truce with Steve Rogers and Bucky Barnes, the three are treated to some video footage in which a brainwashed Bucky murders Tony’s parents in cold blood.

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So, Tony wants to kill Bucky, Steve wants to protect his best friend, and the Avengers are torn apart. In the final moments of the fight, Tony looks into Steve’s eyes and sees that, at least for a second, Steve is willing to kill him.

Worst: Thor: The Dark World

Thor in London in Thor: The Dark World

2013’s Thor: The Dark World is often called the MCU’s worst movie, and that’s probably because it’s the one that most closely follows the franchise’s rigid formula. Whereas directors like James Gunn, Taika Waititi, and Ryan Coogler have each brought a unique vision to their Marvel movies, Alan Taylor directed The Dark World the same way he would direct a TV episode — a cookie-cutter installment, designed to fit the house style.

The third-act battle is no different. A major city is at stake and the villain’s vague evil plan is almost complete. Thor defeats Malekith in the dullest, most predictable way imaginable.

Best: Avengers: Endgame

The Avengers assemble in the final battle of Endgame

The final battle in Avengers: Endgame wasn’t just the climax of the movie; it was the climax of the entire Infinity Saga, 11 years in the making.

Kicking things off with the breathtaking “portals” sequence, the Russo brothers managed to cram in every possible instance of fan service they could find room for: Captain America wielding Mjolnir, Valkyrie riding into battle on a Pegasus, Giant-Man punching a Chitauri Leviathan out of the sky, Pepper Potts wearing a suit of armor, Captain Marvel singlehandedly taking down a warship, and of course, Iron Man making the ultimate sacrifice to save the universe from Thanos’ wrath.

Worst: Iron Man 2

Tony Stark and James Rhodes in Iron Man 2

After the runaway success of the first Iron Man movie, a near-perfect superhero blockbuster that was unfortunately overshadowed by The Dark Knight in 2008, anticipation for the sequel was high. Unfortunately, it failed to live up to expectations. Whiplash was nowhere near as interesting a villain as Obadiah Stane, and the plot seemed more concerned with setting up future MCU installments than telling its own story.

In the final battle, Rhodey finally became War Machine and joined forces with Iron Man to take down Whiplash and his robot army. It should’ve been an awesome sequence, but it’s lazily written. The heroes defeat Whiplash with a fluke, experimenting with firing repulsor blasts at each other.

NEXT: MCU: The 5 Best (And 5 Worst) Movies In The Infinity Saga