- Every time Don starts bickering with a lawyer. Until he starts getting mad, that is...
- S2 E8: Though they are talking about Megan's recent trauma, Larry manages to invoke this.
Larry: This is not even taking into account the double-X chromosome situation.
Larry: Yeah, you know, women have two X chromosomes, men have an X and a so-called Y. But I think if you examine it closely, you'll find, as I have, that the 'Y' is really just an 'X' with a piece missing.
Charlie: Implying what?
Larry: Well, since I'm missing that very piece, I may not be qualified to answer, but I think it has something to do with, you know, they're just more sensitive.
Charlie: Or that they can bear children?
Larry: Eh, psh, that too, I guess.
- Sometimes Charlie's need for data can provide a few laughs.
Charlie: And can I also see all the arson records you have in the L.A. county you have access to for, like, the past year?
Arson Inspector: That's several thousand fires.
Larry: (to Charlie) Eh, that's a pretty limited sample.
Charlie: You know what...make it the past two years.
- "What flavor of crazy Kool-Aid do they make you drink in the physics department?"
- Really, Larry is just a fountain of these.
Amita: Oh! By the way, Larry called from his string theory conference. He was confused about something.
Charlie: What, his double-special relativity theory?
Amita: No, whether he was in St. Louis or Cleveland.
Charlie: He's so geographically challenged. Where is his conference?
- This gem, made even better by the WTF face Charlie pulls when he hears it.
Larry: Oh, I rarely dream. I mean, every once in awhile I have this recurring dream in which my Aunt Louise is attempting to consume my flesh, but as a general rule, no.
- In S2 E23, Colby and David are visiting an Asian strip club. They...don't exactly blend in.
Colby: We're the only white people in here.
(Beat, David looks at Colby)
David: Yes, we are.
- Alan and Larry having to deal with the annual tradition of students dropping pumpkins frozen with liquid nitrogen from the University's rooftops.
- Followed by Charlie's reaction when Alan and Larry decide "when you can't beat 'em, join 'em":
Amita: What was that all about?
Charlie: The two great adult influences on my life are heading off to blow up pumpkins.
- In the episode 'Arrow of Time', several prisoners broke out using a rope made out of dental floss. Liz showed Larry, Charlie, and Amita the rope and this exchange took place:
David: (referring to a rope made of dental floss) It's 30 feet long...
Amita: Floss is sold in containers of 20 to 150 yards... (gets questioning glances) I'm an informed shopper.
Charlie: Just eyeballing the density of this rope, I'm thinking it's gotta be... 18, maybe 19 thousand feet.
Larry: 3 and a half miles of dental floss, even assuming an average container size of 50 yards...
Amita: Mm, 127 rolls of floss.
Liz: You guys find new and special ways to freak me out all the time.
- The end of the fourth season episode Graphic, featured this exchange between comic book artist Ross Moore and Alan Eppes:
Alan: I — I have a little trouble picturing you as a hippie.
Ross Moore: (surprised) Whaaat??
Alan: ... Right!
- 'Black Swan' has a few good quotes when the team are breaking into a house full of bomb making equipment:
- Megan has just crashed into the suspects car to distract them.
Megan: Oh my God, this is why you aren't supposed to text and drive!
- Colby is about to climb up the trellis to get into a upper floor window.
Colby: Yeah. Colby, go down the elevator shaft. Colby, jump in the bay. Hey, Colby, climb the Sixth Street Bridge.
David I went out on the bridge with you, okay?
- A good quote about the running gag:
David: Why do they always run?
Colby: 'Cause we wear suits, man. You always figure you can outrun a guy in a suit.
- Alan being a dad raises a smile every now and again.
Alan: I hear Robin's back in town.
Don: Yeah, I'm really happy she's back.
Alan: Did you tell her that?
Don: Not yet, not in words, no.
Alan: You know, it's guys like you that make Beyonce sing that "Single Ladies" song.
Alan: Great! Now I have two jaded, world weary sons!
Don: And this one's got a shrink to prove it
- After the house has been broken into and both sons are off to a crime scene:
Alan:Two sons that solve crimes and neither one cares.
- Then he gets his own back later during Charlie's leature:
Charlie: I can't believe it. Right in the middle of my lecture!
Alan: Charlie, I'm as embarrassed as you are
Charlie: You were snoring!
- Charlie's examples are always good:
- The one set in the Arctic and he's wearing an heavy coat.
- The one in 'Jacked' at a card table where Charlie is wearing a card dealer's outfit with Don and the bad guy sitting at the table wearing tuxedos, sunglasses and smoking big cigars.
- And occasionally Charlie changes the analogy:
Charlie: You know I, I've been running expressions assuming a dog chasing a cat. But its actually a dog chasing a cat, chasing a mouse!
Ian: I thought it was an airplane?!
Charlie: Oh well, cats and dogs work better now.
- An episode in Season 5, where the whole episode was rather bizarre (they were looking for a specific pair of shoes, for Christ's sake! Well, the shoes were worth like a quarter of a million dollars, but anyway...), but all of the wtf-ness of the episode was made up for entirely when at the end of the episode, when they've finally pinned the shoes. The dude who stole them, also the original victim, goes into his closet, takes out a box... and doesn't find them there. They then hear footsteps outside... and find out that the thief's son was wearing them, in the rain. Apparently he thought they were a birthday present. The thief says, "New shoes... $250,000...". One of the agents then replies, "A smile on your kid's face: Priceless".
- David and Nikki attacking the guy built like a sumo wrestler and Liz beating him with a fire hose.
- The episode "Frenemies" has Charlie reluctantly working a case with his arch rival Marshall Penfield. Naturally the two of them can't stop bickering, prompting a bored Larry to make the following threat:
Larry: Boys, don't make me pull the Math Car over...
- The B-plot in the episode "Old Soldiers" involves David asking Amita for help buying a suit for an upcoming date, but she has trouble meeting his very...particular tastes. At the end of the episode she finds the perfect suit for David — an old one of Alan's from the 70s that she finds while she and Charlie are helping Alan sort through some old things in the garage.
- Agent Edgerton and Don are bickering in front of a suspect about to go into a conversation with some very scary people while wearing a wire.
Don: Don't worry, you got the fifth-best shot in the world covering your [expletive deleted].
Edgerton: [holds up shaking hand] Fourth-best. [looks at his hand] You don't want to know how I moved up a spot.