Raj: I've been plenty of times. If I miss one, it's fine. I'm a big boy.
Sheldon: I'm a big boy, and if I missed one, I'd throw a big-boy tantrum.

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.

Penny: So, do you want to come?
Amy: No, thanks. I already live in a place all the nerds come to.

Raj: Oh, Double Stuf Oreos, I remember when I could afford you.

Sheldon: He also has a remarkable amount of credit card debt.
Howard: I thought your dad paid your cards.
Raj: I have a card for emergencies that I pay for myself.
Sheldon: What emergency happened at the L.A. Zoo?
Raj: That's a penguin I sponsor. They're losing their homes to global warming, and my car gets, like, seven miles a gallon, so I felt bad.