Sheldon: Would you like to play a physics car game I invented called "I Can't Spy?" It's all the nail-biting tension of I Spy but the added fun of sub-atomic particles and waves outside the visible spectrum.
Leonard: If it's half as much fun as "1 x 10 to the 4th bottles of beer on the wall", I'm in.

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: Have you made a decision about the TARDIS? I think I can sell it if we call it Big British Portapotty.

Sheldon: Play that funky music, white boy.
Leonard: I'm surprised you know that reference.
Sheldon: What reference?

Bernadette: Hey, Raj, if Howard can't keep the TARDIS, how great would it look at your place?
Raj: What?
Howard: Yeah, what?
Bernadette: I don't know much about Doctor Who, but if you were to put this right outside your front door and open up the back, it would be like your entire apartment is the inside of the TARDIS. Which is pretty cool because on the show, the inside of the TARDIS is bigger than the outside. But then again, I don't know much about Doctor Who.