Penny: Okay, Beverly, aren't you overreacting a little? All we know is they shared a cab and had a nightcap.
Sheldon: And turned their phones off.
Leonard: Not helping, buddy!

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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

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.

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.

Raj: Can we take a moment to discuss that I just lied to the government for you?
Howard: Yeah, I would not have done that for you.

Sheldon: Do you think your father's doing unspeakable things to my mother?
Leonard: No.
Sheldon: Are you saying that because the things are unspeakable?
Penny: Your parents are old. Anything unspeakable was finished by 9:30.