When CSI debuted in 2000, no one could have predicted what a pop-cultural smash-hit it would become. The original incarnation lasted for fifteen seasons, spawned three spin-off shows, and changed the way that people thought about criminology. There is an actual phenomenon known as "The CSI Effect" that refers to how the show has colored jury expectations about forensic science.
Spanning three hundred and thirty-five episodes, the show has run the gamut between excellence and abhorrence.
Updated on November 27th, 2021 by Tanner Fox: Though it technically concluded in 2015 after fifteen years on the air, CSI is still a major influence on modern TV. Be it a spin-off series like CSI: Miami and CSI: Vegas or a similar series like Bones or Criminal Minds, CSI's impact isn't likely to be erased any time soon.
Though the show premiered well over 300 episodes during its run, only a few managed to meet a mark of 8.5 or greater on IMDb. That said, certain standout episodes were particularly appealing and remain in the minds of fans more than a decade later.
"Loco Motives" (Season 7, Episode 10) - 8.6
In this season seven episode, Willows and Brass encounter a man claiming to have the worst luck in the world. Half-buried in concrete next to a dead woman whom he refuses to identify, the team unravels a comedy of errors that landed the man in some wildly unfortunate circumstances.
There's a lot of levity in this episode, making for a stark contrast between many of the tension-filled outings which tend to rate highly among audiences. However, the episode also features the famous Miniature Killer, making it automatically memorable.
"Ending Happy" (Season 7, Episode 21) - 8.6
Lorenzo "Happy" Morales was an over-the-hill boxer who spent much of his time at Sugar Cane Ranch, which is actually a brothel. After his lifeless body is seen floating in the pool one morning, the team comes in to investigate. While Happy is initially said to have been a well-liked ex-athlete, a deeper investigation reveals a history of debauchery and violence.
A quintessential CSI episode, audiences ought to be at the edge of their seats, as every moment sees a new revelation come to light. Well-paced, engaging, and with just enough humor to not be overly serious, it's an excellent inclusion in an already well-liked CSI season.
"Monster In The Box" (Season 7, Episode 16) - 8.7
Serial killers are the boogeymen of any police procedural, and CSI had more than its share of them. The Miniature Killer first appeared in season seven, and, after committing a murder, the killer would then assemble a meticulous scale model of the crime to be left at the scene or to be mailed to someone involved in the case.
"Monster In The Box" begins with Gil Grissom receiving a package containing a miniature depicting a crime that hasn't happened yet. This sets the team on a mission to find the woman depicted in the model before she can become the killer's next victim.
"Blood Drops" (Season 1, Episode 7) - 8.7
One of the most extreme episodes of the series, this season-one story sees the team tackle a mysterious middle-of-the-night quadruple homicide. The introduction is almost something out of a horror movie, and it's a tightly-paced and harrowing watch the entire way through.
There's never a dull moment in this episode, and, be it the intense examination of a particularly grizzly crime scene or the surprisingly tender moments between the young Brenda and the relatively unenthused Sara, there's a lot to like about "Blood Drops."
"Turn, Turn, Turn" (Season 9, Episode 16) - 8.7
The crime scene investigators often got personally involved in the cases they worked, and, when they did, some of the best episodes in the series. "Turn, Turn, Turn" focuses on Nick Stokes taking on the case of a girl he got to know while working separate cases at the seedy roadside hotel where she lived.
Chronicling Stokes' growing friendship with the girl over a year, with George Eads turning in one of his best performances. By the end of the episode, Nick is haunted by the question of whether he could have helped the girl. Chances are the audience will too.
"Ms. Willows Regrets" (Season 12, Episode 11) - 8.7
As with so many episodes of CSI, this one starts with the victim's bodies being found in the desert. Three sets of skeletal remains are found in a barrel, and, when the bodies are identified, they turn out to be a lawyer and his two employees with whom Catherine Willows was familiar. She had previously had recommended the man to a friend who was seeking to divorce her abusive husband.
This episode sets up Catherine's eventual exit from the show and her struggle with the fear that she might have somehow been responsible for the man's death is quite compelling.
"Lady Heather's Box" (Season 3, Episode 15) - 8.7
Another classic tale of scandal, this season three episode is rife with strange twists and weird intricacies. When male prostitutes start turning up dead under mysterious circumstances, the team must put their deductive capabilities to the test and traverse a wild world of borderline-criminal perversions.
It's definitely a bit of an oddball episode, but that may be what makes it so appealing to fans. Additionally, after someone very close to her turns up dead, Willows must overcome an emotional crisis. While undeniably tense, it's a must-see episode for fans of the character.
"Law Of Gravity" (Season 7, Episode 15) - 8.7
When Gil Grissom decided to take a sabbatical from his CSI duties, he is replaced for a few episodes by Michael Keppler, a CSI with a mysterious past. Fans were divided on whether or not he was a worthy replacement for the fan-favorite Grissom, but they seem to agree that his swan song was one of the best episodes of the show.
A face from Keppler's past comes to town looking for a favor, sparking a chain of events that lead to the character's death. Despite his mixed reception, many fans were sad to see Keppler go out the way he does.
"Built To Kill: Part 2" (Season 7, Episode 2) - 8.7
The second installment of a two-part season premiere, "Built to Kill: Part 2" features an eventful story that sets up the rest of the fan-favorite season. After waking up in a seedy motel, Willows must piece together the events which lead her there in a private investigation that takes some pretty harrowing turns.
This episode is particularly well known for the introduction of the Miniature Killer, arguably the most important criminal ever to surface in a CSI storyline. Replete with horrifying discoveries and plenty of intrigue, this episode absolutely deserves to be celebrated as one of the series' best.
"For Gedda" - (Season 8, Episode 17) - 8.8
One of the occupational hazards of a television crime solver is that they may eventually come under suspicion for a crime they are investigating. This exact thing happens to Warrick Brown when he is found at the scene of a murder, the victim chained with his cuffs. A race to prove the CSI innocent follows and reveals a mole in the police.
This episode is the first of two episodes that lead to the death of Warrick Brown. Naturally, they are some of the most emotional in the show, and "For Gedda" sets up this exit beautifully. It's a truly memorable season finale.
"Willows In The Wind" (Season 12, Episode 12) - 8.8
Following on from "Ms. Willows Regrets," "Willows In The Wind" finds Catherine on the run after narrowly surviving an assassination attempt. She must find out who it is who wants her dead in a case where nothing is as it seems.
This episode marks Catherine Willows's departure from the main cast of the show. Her farewell is an emotional one, as, to this point, she had been one of the last remaining members of the original cast. She does show up for the two-part series finale, "Immortality," and, though this episode aired in the show's declining years, it still managed to be a fan favorite.
"Gum Drops" (Season 6, Episode 5) - 8.9
Crimes involving children are considered especially horrible, so episodes of crime dramas focusing on children are sometimes some of the most compelling. In "Gum Drops," the team investigates a bloody murder in a small house on the outskirts of town. While at first, it seems that the entire family has been killed, Stokes has a hunch that the youngest daughter Ellie is still alive.
The episode is named after the wads of chewed gum that Ellie leaves as clues. The girl's cleverness eventually leads to the team finding and rescuing her from her captors.
"Living Doll" (Season 7, Episode 24) - 8.9
Another danger to television law enforcement is that they may eventually become the target of the killer that they have been hunting. This happens to Sarah Sidle, who is targeted by The Miniature Killer. Captured and left in a death trap, the team must race to find their friend before she becomes the murderer's latest victim.
Another memorable season finale, this episode features some of the most striking imagery in the series. From the shot of Sarah's hand reaching out from an overturned car to the killer slashing Grissom's throat in a hallucination, there are some memorable scenes in this episode.
"One To Go" (Season 9, Episode 10) - 9
Gil Grissom was the first leader of the CSI team, and he is probably still the character most associated with the show. His departure marked a turning point in the show, and he leaves on a memorable note. Racing to find the Dick and Jane serial killer, Grissom reaches out to criminology professor Raymond Langston.
After the death of Warrick Brown earlier in the series, it was gratifying to see Grissom get to ride off into the sunset alive and at peace to be with the woman he loves. This episode also sets up Langston as the new central protagonist of the show.
"For Warrick" (Season 9 Episode 1) - 9.1
When a crime drama needs to drum up excitement for an episode, they often drop the ominous hint that somebody is going to die during the episode. Most of the time, the one to go is a side character and not a member of the main cast as we are led to believe, but, on a few occasions, a character that the audience has come to know and love does meet their end—and, when done right, it's an emotional gut punch.
Directly following the episode "For Gedda," the team must solve the murder of their friend and colleague. Grissom's tearful eulogy is one of the saddest scenes in the entire series.