Leonard: Stuart, have you thought about what you'd do if Howard sells the house?
Stuart: And there goes the mood.

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.

Penny: I mean, who even reads Scientific American?
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

Sheldon: Is it my fault I have a much bigger reputation than he does?
Amy: It's not your fault.
Sheldon: Is it my fault that my name came first on the paper alphabetically?
Amy: Not your fault.
Sheldon: Is it my fault that when the reporter cited me as the lead scientist, I didn't correct him?
Amy: Hey look at that pretty bird.

Howard: All Ma's food is going to be ruined.
Bernadette: Why don't we take it home and put it on our freezer?
Raj: You don't want to do that. Refreezing not only removes moisture, but it creates ice crystals in the fibres of the meat that can compromise its taste and texture. What? I saw a teachable moment. I dropped some culinary science.