Actor-Inspired Element: Gil Grissom wasn't the character's original name, William Petersen dubbed him Grissom after astronaut Gus Grissom because he (Petersen) was a fan of the space program. Considering the original surname for the character was Scheinbaum, this was probably an upgrade.
Cast the Expert: David Berman, who was a real life coroner before playing 'SuperDave' Phillips, the coroner's assistant.
Cowboy BeBop at His Computer: Dr. Raymond Langston is not Grissom's replacement, instead coming in on the bottom rung. Though that doesn't explain why he got to be first in the opening titles, something his character really hasn't earned.
He's a Renaissance Man; he's only a Level 1 CSI (though he works his butt off to get quickly promoted to Level 2) but he used to be a medical doctor (so he assists in autopsies more than most) and a criminology lecturer (so he occasionally provides a criminal profile). He's under-qualified as a crime scene investigator but he makes up for it with a broad range of skills. Plus he's Laurence Fishburne.
I Am Not Spock: Petersen learned sign language for the episode it was in, but fans have tried speaking to him in sign not realizing he doesn't really know it.
McLeaned: Averted. Despite contrary belief, Gary Dourdan's drug charges in 2008 was not the reason why his character was killed off in the season nine premiere. In fact, said charges happened after contractural negotiations had concluded.
The Other Darrin: Ellie Brass, who was played by two different actresses in 'Ellie' and 'Hollywood Brass' plus 'Bang Bang'. Also Lindsey Willows, but hers is probably a bit more justified since she was a child and growing up fast and the earlier actresses may not have been available.
Marg Helgenberger and Jorja Fox do not voice Catherine or Sara in most of the games.
Produced by Cast Member: William Petersen served in the capacities of producer, supervising producer, co-executive producer and executive producer for various lengths of time throughout the series' entire 15-year run.
Real-Life Relative: Marg Helgenberger's now-ex-husband in two episodes (Weeping Willows and one more).
Sort of with Gina Torres and Laurence Fishburne, only Torres guest starred during season four, six seasons before her husband became the series lead.
Reality Subtext: Sara Sidle is a vegetarian. So is her actress, Jorja Fox (as was one of Fox's previous characters, ER's Dr. Maggie Doyle)
Role-Ending Misdemeanor: Nick was written out of several Season 14 episodes after George Eads had a row with a female writer.
Lampshaded in an episode where they become the subject of a Show Within a Show and mention that everything is edited together to make it look faster.
Also lampshaded in a later episode when Hodges mentions that he's convinced everyone that most of the advanced equipment he operates takes twice as long to work as it actually does in order to get more free time.
Note that on many occasions the characters complain about the lack of useful fingerprints, and sometimes the fingerprint collected doesn't match anything on the Omniscient Database.
They subverted this in one episode - a cleanly lifted print in an old case is shown to be fabricated because there was no way that it could have been lifted from the surface claimed (an alligator-skin wallet).