Penny: Normally, I can just ignore you. I mean, I get it. You're a little peculiar. Like Sheldon.
Sheldon: Excuse me, Penny, but in this room, you're the one who's peculiar.

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.

Barry Kripke: We're all pathetic and creepy, and can't get girls. That's why we fight robots.

Mrs. Wolowitz: Want me to get you a popsicle?
Howard: Cherry, please!
Mrs. Wolowitz: I ate the cherry. All that's left is green.
Howard: You make me wanna kill myself!

Mrs. Wolowitz Howard, there's a blonde girl, Patsy, here to see you.
Howard: Who?
Mrs. Wolowitz Okay, now she's saying it's Penny.