Leonard: I'm the king of foreplay.

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?

Sheldon: Oh, what fresh hell is this?
Biosuit Nurse: Wait, you can't leave here, you've been exposed.
Sheldon: (Covering his face with his shirt) No, I haven't. It's all good.

Howard: Hell hound.
Raj: Who let the satanic dogs out?

Raj: Sheldon, that's my water.
Sheldon: Oh, dear Lord!
Leonard: That's not your water.
Raj: I know.