Bernadette: Raj, when you said you were going to bring a date to watch Penny's thing tonight, I didn't think you meant Stuart.
Howard: Really? I never for a second thought it'd be anything else.

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.

Amy: Do you have any idea how hard it is to laugh at a knock knock joke that starts "Knock Knock Knock, Amy. Knock Knock Knock, Amy. Knock Knock Knock, Amy"?

Bernadette: (Shouting from the bathroom) How many times do I have to tell you to replace the toilet paper when it's empty?
Howard: I'm in the middle of something.
Bernadette: So am I!

Penny: I just got a part on a TV show.
Amy: Congratulations!
Leonard: That's great. Guys ...
The guys: Yeah ...
Amy: What's the show?
Penny: NC - I I? or, you know, NC - S T D. I don't know. It's the one with all the letters.