Leonard: Where have you been?
Sheldon: Oh, Leonard, if I was prone to sarcasm I'd say I was pulling off a major heist at the museum of laundry baskets.
Leonard: (Counts to 10 and takes a breath) What I meant was, gee Sheldon! You were gone a long time!

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: 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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Bernadette: I told you you shouldn't have espresso after dinner. I know the little cups make you feel big but it's not worth it.

Bernadette: You can't just throw everything in the closet.
Howard: Hey, you can tell me what to do and how to do it, but not both at the same time. This isn't sex.

Sheldon: What can I do for you ladies?
Amy: You have something we want.
Sheldon: Oh, dear. My mother warned me this is what happens to pretty boys in the big city.
Penny: No, we just want information.
Sheldon: Oh. I've got that spades. Ravage me.