Sheldon: My shirt is itchy and I wish I were dead.

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.

Bernadette: I told you you shouldn't have espresso after dinner. I know the little cups make you feel big but it's not worth it.

Sheldon: What can I do for you ladies?
Amy: You have something we want.
Sheldon: Oh, dear. My mother warned me this is what happens to pretty boys in the big city.
Penny: No, we just want information.
Sheldon: Oh. I've got that spades. Ravage me.

Sheldon: Did you also have a dog? Because I found what appears to be a battery-operated chew toy.
Penny: Party's over. Party's over.