Penny: What would you recommend as a present for a 13-year-old boy?
Stuart: A 13-year-old girl.

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.

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.