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.

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

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.

Sheldon: You may not be as academically inclined as are we. Yes, that's how you say it. But you possess an intelligence I envy, which leads me to my answer. I would choose the ability to read people's minds.

Patent Attorney: And as far as Mr. Wolowitz is concerned, I'm afraid as a federal employee on loan from NASA, your name can be on the patent, but you're not entitled to an ownership share.
Howard: Wait, so this can turn out to be a financial success, and I get nothing?
Patent Attorney: Well, sometimes they give you a plaque.
Sheldon: Well, that's not fair. We should all get plaques.

Howard: You have any idea what you're getting Sheldon for his birthday?
Raj: He's been fascinated with dinosaurs lately. Maybe we could get him a fossil.
Leonard: Well, just don't get anything Jurassic. He feels like that whole chunk of time has gone Hollywood.

Mrs. Wolowitz:What's going on? Are you boys rough housing?
Howard: We're just talking, Ma!
Mrs. Wolowitz: If you don't settle down right now, I'm not gonna let you have any more sleepovers.
Howard: For God's Sake, Ma, I'm 27 years old. And it's not even a school night.