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: 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.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

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.

Sheldon: Did you also have a dog? Because I found what appears to be a battery-operated chew toy.
Penny: Party's over. Party's over.

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.