Penny: Come on, let's just get this over with.
Leonard: "Let's just get this over with?" Am I driving you to the Cheesecake Factory or are we having sex?

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Bernadette: Raj, your tag's sticking out. *Bernadette tucks Raj's clothing tag back in*
Raj: Thank you. That's the closest I've come to sex in like two years.
Bernadette: Now I feel a little gross.
Raj: You're only making it seem more real for me.

Sheldon: I have one question. Is this a prank? Where you land in Houston and you've made up wanted posters which have my face with a moustache and a Spanish name, and I get arrested and deported to South America?
Howard: No.
Sheldon: Well I'm glad, because I would not have seen that coming.

Howard: Listen, I was thinking you and I could probably try to be better friends.
Sheldon: Really? I was thinking what we have now is a bit much.