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.
Leonard: I don't want tea.
Sheldon: I didn't make tea for you. This is my tea.
Leonard: Then why are you telling me?
Sheldon: It's a conversation starter.
Leonard: That's a lousy conversation starter.
Sheldon: Oh, is it? We're conversing. Checkmate.
Sheldon: I wouldn't tell you the secret. (pause) Shhhhh!!!!
Leonard: What secret? Tell me the secret.
Leonard: Not that secret, the other secret.
Sheldon: I'M BATMAN!!!! SHHHH!!!
Sheldon: I'm not insane, my mother had me tested!
Sheldon: No, the X-men were named for the X in Charles Xavier. Since I am Sheldon Cooper, you will be, my C-men.
Sheldon: At my age do you know how I'm statistically most likely to die?
Leonard: At the hands of your room mate?
Sheldon: An accident.
Leonard: That's how I'm going to make it look.