Leonard: Listen, I should warn you that maybe asking Amy out isn't a good idea.
Sheldon: Barry, a word?
Leonard: And now the crazy version of what I just said.
Sheldon: If you intend to pursue Amy, you leave me with no choice but to put a stop to it.
Barry Kripke: And how are you gonna do that?
Sheldon: By challenging you to a duel.
Barry Kripke: You've had one lesson. I'll destroy you.
Sheldon: That is why the duel will take place at high noon, three years from today. If you're worth your salt as an instructor, I should be ready by then.
Yeah, and be warned. I'm going to touch you all over.
Leonard: Wow, that was crazier than I thought.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: Why are you crying?
Penny: Because I'm stupid.
Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Howard: My name is Inigo Montoya. You killed my father. Prepare to die.

Raj: My name is Little Orphan Annie. You killed my father. Prepare to die.
Howard: My name is Darth Vader. I am your father. Prepare to die.

Bernadette: Stuart took that rejection like a pro.
Penny: Well, he knew he was on the breast cam.
Amy: I don't have much practice turning men down. It wasn't so much fun.
Bernadette: Oh, you get used to it. Some guys you have to turn down over and over.
Penny: And sometimes we marry them anyway.