Leonard: Oh, hey, Stuart. This is Penny. She's looking for some comic books.
Stuart: Oh, really? Blink twice if you're here against your will.

Stuart: Oh, Sheldon, I'm afraid you couldn't be more wrong.
Sheldon: More wrong? Wrong is an absolute state and not subject to gradation.
Stuart: Of course it is. It's a little wrong to say a tomato is a vegetable, it's very wrong to say it's a suspension bridge.

Stuart: Would you mind stocking these?
Denise: Actually, I'm not on the clock today. I'm just hanging out with my boyfriend.
Stuart: Ah, cool. Huh. That's me, right?
Denise: Oh, I forgot to tell you, I broke up with you, and now I'm dating that guy.
Stuart: I know you're joking, but my flight-or-flight response doesn't.
Denise: Isn't it fight-or-flight?
Stuart: Not for me.

Stuart: Whoa, whoa. You're not gonna cut open a meteor, are you? Have you not learned anything from comic books? Space viruses? Pod people? I sell nothing but warnings.

Stuart: Oh, Sheldon, I'm afraid you couldn't be more wrong.
Sheldon: More wrong? Wrong is an absolute state and not subject to gradation.
Stuart: Of course it is. It's a little wrong to say a tomato is a vegetable, it's very wrong to say it's a suspension bridge.

Wolowitz: I'm a horny engineer, Leonard. I never joke about math or sex.

Howard: Are you familiar with the Drake Equation?
Sheldon: The one that estimates the odds of making contact with extraterrestrials by calculating the product of an increasingly restrictive series of fractional values such as those stars with planets, and those planets likely to develop life? N equals R times FP times NE times FL times FI times FC times L?
[pause]
Howard: Yeah, that one.