Raj: So you're wandering all around by yourself? That's not the kind of hero's welcome an astronaut should come home to.
Howard: It's okay. You know, we space cowboys don't do what we do for glory and fame. We leave that to your rock stars and your athletes and your Howie Mandels.

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.

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

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

Howard: Wow, so you guys are like buds now?
Raj: Oh, yeah, we hang out all the time.
Stuart: Plus, he doesn't have a girlfriend, I don't have a girlfriend.
Raj: It's like we both had these holes in our lives, but now we fill each other's holes.
Stuart: That sounds a little funny to an American ear.
Raj: Which part?
Stuart: Just all of it.

Amy: We could go to the cadaver lab at UCLA and play real-life Operation.
Leonard: Uh-uh.
Sheldon: No.
Penny: I don't think so.
Amy: Are you sure? I mean, the nose doesn't light up, but if the corpse is fresh enough, sometimes you can get the leg to jerk.

Penny: You're unbelievable.
Sheldon: I know.