Sheldon: My father used to say that a woman is like an egg salad sandwich on a warm Texas day.
Alex: What?
Sheldon: Full of eggs and only appealing for a short time.

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: I have a lab full of coked up monkeys with nothing to lose.

Alex: Is there a problem?
Sheldon: Let's not call it a problem. Let's call it an opportunity. To solve a serious problem.

Raj: I did the research. Tony the Tiger, Dig'em the Frog, Cap'n Crunch, Toucan Sam, Count Chocula, Trix the Rabbit, Snap, Crackle and Pop. Not one cereal mascot is a girl. It's a total breakfast sausage fest.
Leonard: Are we done with this?
Raj: Almost. Franken Berry, Boo Berry, Sugar Bear and the Honey Nut Cheerio bee, I believe his name is Buzz.