Leonard: What was the plan?
Penny: Um, waitress for six months and then become a movie star.
Leonard: Was there a Plan B?
Penny: TV star.

Sheldon: Leonard, you can't train my girlfriend like a lab rat
Leonard: Actually, it turns out I can
Sheldon: Well you shouldn't

Sheldon: Are you asking me or telling me?
Leonard: Telling you?

Sheldon: That's not an apology; that's simply an acknowledgment that I was right.
Leonard: Okay, I'm sorry.
Sheldon: There you go.

[knock] Amy. [knock] Amy. [knock] Amy.

Open the landing bay doors, shuttle craft approaching.

Oh, no, he's gonna telecommute. Everybody's really excited about it.

Leonard: In what universe is that a present?
Sheldon: It's not a present. It's the present. There's you and me. It's Penny and Amy. We're playing Pictionary. In the present.

Leonard: I'm going to the movies with Penny. I don't want her to think I think it's a date
Sheldon: Do you think it's a date?
Leonard: No, but she might think I think it's a date even though I don't.
Sheldon: Or you might think she thinks you think it's a date even though she doesn't.
Leonard: Are we over thinking this?
Sheldon: Not at all.

Leonard: No, I'm done with Penny. I'm going to be more realistic and go after someone my own speed.
Raj: Like who?
Leonard: I don't know... Olivia Geiger?
Sheldon: The dietitian at the cafeteria with the limp and lazy eye?
Leonard: Yes.
Sheldon: Well, I don't think you have a shot there

Leonard: Hey, how's it going?
Wolowitz: Cut the crap, you set this up, didn't you?
Leonard: Yes..
Wolowitz: She's a hooker, isn't she?
Raj: A prostitute, yes
Wolowitz: You already gave her the money?
Leonard: Yes
Wolowitz: ... Thank you

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

TBBT Quotes

Penny: Here's a question-- as an alien pretending to be human, are you planning to engage in any post-prom mating rituals with Amy?
Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.
Sheldon: Well, if it's part of the prom experience, then I'm open to it.
Penny: You're kidding.
Sheldon: I may be an alien, but I have urges.If Amy wants to copulate by firing her eggs into space, well, then, I will happily catch them with the reproductive sac on my upper flermin. I'm not the best at reading facial cues, but I can see that you're a little turned on.

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny, get your own Wi-Fi." No spaces.