Sheldon: Well, what do you know? Here I was, waiting to be bored with biology, and instead you tickle my intellectual fancy. Which, unlike my body, is an okay place to tickle.

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.

Amy: Why don't you ask me what I'm working on?
Sheldon: Oh, very well. What have you been working on? And feel free to honk during the boring parts.

Amy: Wait, are you saying if we combine my experiment with your calculations, we can determine the precise moment in time when the wave function collapses?
Sheldon: It could be the most inspired combination since I mixed red Icee into my blue Icee. It was like drinking 2/7ths of the rainbow.
Amy: Sheldon, this is really interesting.
Sheldon: Yeah and this one won't stain my teeth purple.

Leonard: Oh, it's just nice to be with people who are happy to have me around. Isn't that right, Halley?
*Halley starts crying*
Howard: Well, at least someone had the courage to say it.