Leonard: What happened?
Penny: Well, I went over to Mike's to make up with him.
Leonard: Yeah. No, I know that part.
Penny: But he had already moved on.
Leonard: Already? That was quick.
Penny [crying]: That's what I said to the woman who had her legs wrapped around his neck!

Leonard: Why are you learning Chinese?
Sheldon: I believe the Szechuan Palace has been passing off orange chicken as tangerine chicken, and I intend to confront them.
Leonard: If I were you, I'd be more concerned with what they're passing off as chicken

Leonard: I don't think I can go out with [Penny] tonight.
Sheldon: Then don't.
Leonard: Other people would say, "Why not?"
Sheldon: Other people might be interested

Penny: Yes, I will go out with you.
Leonard: Really?
Penny: Yeah. Why not? I mean, what do I have to lose?
Leonard: Yeah. That's the spirit

Penny [referring to Sheldon]: What's up with Ichabod?
Leonard: Oh, he's trying to make a new friend
Penny: Well good for him
Leonard: Unless he makes one out of wood like Geppetto, I don't think it's going to happen

Leonard: [Sheldon] says he's moving out.
Raj: What did you do? Did you change the contrast or brightness settings on the television?
Leonard: No.
Raj: Did you take a Band-Aid off in front of him?
Leonard: No.
Wolowitz: Did you buy generic ketchup? Forget to rinse the sink? Talk to him through the bathroom door?

Penny: So it's fine with you if I'm not smart.
Leonard: Absolutely. [Penny closes the door on him] Okay, this time I know where I went wrong

Leonard: What do you mean, you're moving out? Why?
Sheldon: There doesn't have to be a reason.
Leonard: Yeah, there kinda does.
Sheldon: Not necessarily. This is a classic example of Münchhausen's Trilemma. Either the reason is predicated on a series of sub-reasons leading to an infinite regression, or it tracks back to arbitrary axiomatic statements, or it's ultimately circular, i.e. I'm moving out because I'm moving out.
Leonard: I'm still confused.
Sheldon: Leonard, I don't see how I could have made it any simpler

Leonard: How could you just sit there and let them spy on me?
Sheldon: They were clever, Leonard. They exploited my complete lack of interest in what you were doing

Sheldon: Why should I leave? This is my apartment, too.
Leonard: I know it is. And if science ever discovers a second member of your species, and you two would like some privacy, I'll be more than happy to get out of your way

Leonard: If we do get a new friend, he should be a guy you can trust. You know, a guy who has your back.
Wolowitz: And he should have a lot of money and live in a cool place down by the beach where we could throw parties.
Sheldon: And he should share our love of technology.
Wolowitz: And he should know a lot of women.
Leonard: Okay, let's see: money, women, technology. Okay, we're agreed. Our new friend is going to be Iron Man

Leonard: At least I didn't have to invent 26 dimensions just to make the math come out.
Sheldon: I didn't invent them, they are there!
Leonard: In what universe?
Sheldon: In all of them, that's the point

TBBT Quotes

Oh, Bernadette, please play my clarinet.

Raj's poem

Sheldon: I'll have a diet Coke.
Penny: Can you please order a cocktail? I need to practice mixing drinks.
Sheldon: Fine... I'll have a virgin Cuba Libre.
Penny: That's... rum and Coke without the rum.
Sheldon: Yes, and would you make it diet?