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.

Josh: So, I have to ask, was the robot sexy?
Howard: It was actually just a mechanical hand.
Josh: 'Cause that's all you need, right?
Howard: You are my brother.

Sheldon: Sheldon Cooper does not cry.
Howard: That's true, you'd rust.

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.