Raj: What's that?
Howard: Sounds like a cricket.
Sheldon: Hang on. Based on the number of chirps per minute and the ambient temperature in this room, it is a snowy tree cricket.
Howard: Oh, give me a frickin' break. How could you possibly know that?
Sheldon: In 1890, Emile Dolbear determined that there was a fixed relationship between the number of chirps per minute of the snowy tree cricket and the ambient temperature. A precise relationship that is not present with ordinary field crickets.
Raj: How do you know what the exact temperature of the room is?
Sheldon: Under the terms of my roommate agreement with Leonard, I've had unilateral control of the thermostat ever since the sweaty night of '06.

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.

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.

Wolowitz: I think that you and Penny had a poor night.
Leonard: It wasn't poor. It was ... just fine.
Raj: Dude, the fourth Harry Potter movie was just fine.

Raj: Ooo, big talk from a man who was once treed by a chicken.