Wolowitz: *After he fixed Sheldon's algorithm* Gee, why can't Sheldon get a friend?

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Howard: So you can never take it (the sweater) off?
Leonard: No.
Raj: Not even to sleep?
Leonard: No.
Howard: So you're just an idiot?
Leonard: It's called proving a point.
Howard: Is the point you're an idiot?

Bernadette: Maybe we should get one of those machines to help her up the stairs.
Howard: You mean a fork lift?

Sheldon: A fear of heights is illogical. A fear of falling, on the other hand, is prudent and evolutionary.

Sheldon: What part of an inverse tangent approaching an asymptote don't you understand?

Sheldon: "Barney Bunny has two daddies now." Probably something about homosexual rabbits.