The glorious Kansas City Shuffle by the villains in the episode "Suckers". There's a murder (fake), to cover a robbery (also fake), to cover an art forgery (fake again), to distract from a casino heist (quasi-fake)... all leading up to an insurance scam by the promoter of the art exhibit — and he admits it to Grissom's FACE at the end of the episode. Crime has never looked so diabolically cool — and not a single murder to be seen. The fact that the entire episode had backup music by Gilbert and Sullivan is just gravy at this point.
Grissom admits that he cannot prove the insurance scam in a court of law. He will, however, just turn everything over to the insurance company, and let them handle it.
When Greg Sanders is interrogated at an inquest to determine his culpability in running over a proven murderer, he was accused by a judge of drinking prior to the event. After a second of panic, Greg proceeded to, calmly and systematically, prove exactly why the very little alcohol he consumed many hours earlier had no effect on him, performing a multitude of calculations in his head as he explained them to the jury. The judge was thoroughly humiliated.
Also, the event that led to Greg's inquest in the first place: After a bit of Car Fu to stop a gang member from beating a tourist, Greg took a severe beating from the rest of the gang, fighting, scratching and getting spat on the whole time. He stayed conscious long enough to give the team a detailed description of the gang, and to tell them he had DNA evidence under his fingernails.
The guy Greg saved got a moment of awesome too. When Greg is being harassed by reporters over the vents, the man comes to his rescue and says Greg saved his life and the reporters should be ashamed for trying to make him feel guilty for running over the attackers. The guy in question being Bobby Singer also helps.
The forensic tour-de-force following Nick's abduction and live burial, in which each and every major character got to contribute some crucial observation or Chekhov's Skill to engineer his successful rescue, was a collective example.
In the episode involving Mickey Dunn, Doc Robbins gets one. He walks into the morgue to find a presumed journalist taking photos of the "famous" skeleton on his table. Robbins demands the camera. The guy pretends to offer it but is clearly thinking "Old man with a stick, no problem", and he tries to force his way past. Approximately ten seconds later, he's groaning on the floor and Robbins is calling for security.
Honestly, the original Mickey Dunn (played by Roger Daltrey no less), for his entire elaborate scheme of string murders while having everyone think he's dead. He appeared in disguise on the news and they still didn't recongnize him.
Only for Catherine (who had a crush on Mickey as a teenager) to totally steal his thunder in the episode's final scene and blow his attempted Thanatos Gambit to itty-bitty bits: Mickey had been shot years before, and although he survived the bullet was slowly migrating to his heart; he decided to kill the people who set him up to die when it was just about to hit, reasoning that even if he got caught he'd die before he did serious time. Sure enough he has a heart attack in interrogation and thinks he's won... only to wake up in a hospital room with Catherine by his bedside, as she calmly explains that with the progress surgery has made since the '70s the doctors were able to save him easily, and he's going to prison for the rest of his life.
Nate Haskell, the serial killer obsessed with Ray Langston (on trial for stabbing said Ray), has managed to get a neurologist to say that Haskell isn't responsible for any of his criminal actions, due to brain damage that is theoretically caused by a specific "warrior gene" anomaly present in Haskell's genome. Ray takes the stand, and during the cross examination (undertaken by Haskell as part of his plan) Ray says that there's no evidence that the gene causes people to become serial killers. When Haskell asks what experience Ray has that allows him to make such a statement, Ray simply and calmly lays out that he has the gene, and has lived his life trying to help people, not hurt them, blowing the defense right out of the water.
Ray: A good lawyer never asks a question he doesn't already know the answer to.
"Malice in Wonderland" Hodges and his mother are being held hostage, restrained and at gun-point, in an ambulance on its way out to the desert, where they'll be left to die. Fed up with his mother's over-idolizing views of him, he goes into a bout of Heroic Self-Deprecation...that ends with him stating that one of the few things he has is "knowledge of the physical limitations of duct tape", at which point he breaks his restraints, disables the person holding the gun with a syringe, and takes the gun, leaving the other crook having to resort to accelerating to the point that shooting him would get them all killed just to keep from being completely owned by the lab rat. Yes, you read that right; Hodges.
Sara can be a polarizing character, but there's no denying that she got one of these in an early episode. The scene is in the interrogation room, where it looks like they're unfortunately going to have to let the rapist/killer go due to Not Proven. Suddenly, in comes Sara with some new evidence: the missing stewardess's suitcase, which went missing with her and which the team had been trying to find through most of the episode. The suspect is incensed; how dare she go through his car without a warrant! Sara unzips the suitcase, and... there's a tape recorder in there. Turns out it wasn't the stewardess's suitcase after all but an identical one, and she just tricked the guy into confessing where he was hiding the real one and got it all caught on tape!
Grissom owning the lawyer's ass in the episode "The Accused is Entitled". A famous movie star has been accused of murdering a girl. He's hired a pretty ruthless lawyer and also Grissom's mentor to decimate the evidence the CSIs have collected during the prelim. Because Grissom was losing his hearing at the time, he's not collected any evidence in the high profile case and throughout the hearing the mentor and lawyer have destroyed every piece of evidence the prosecution has as well as call into question the skills and even character of the CSI team and it looks like the judge will throw the case out even though the accused is guilty. Grissom then decides to take the stand with some evidence he's found so his mentor advised the defense lawyer to "speak softly" so that Grissom will have trouble hearing her. However, Grissom can lip read and after a few times asking her to repeat herself, Grissom answers and provides his evidence flawlessly. Boom! Grissomed!
Doc Robbins saving the baby in "Unleashed". They have stumbled on the scene of a teenage girl's suicide after a passerby stops their car on the way home from breakfast. Robbins stays with the body while Nick heads back to the car to fetch his kit, but Robbins quickly calls Nick back when he realizes that the dead girl was pregnant, almost to term and the fetus is still moving. Using Nick's pocket knife and help Robbins quickly does a C-Section, pulls the baby out and then gives her mouth-to-mouth until she starts breathing and crying.
In "Swap Meet," after a statutory-rapist claims to know the identity of the killer and requests a deal: