Sheldon: I don't understand why you're not enjoying this. Together, in this car, with my enhanced capabilities, we're like 'Knight Rider.'
Leonard: Except, in Knight Rider, the car isn't a yammering sphincter.
Sheldon: You mock the sphincter, but, the sphincter is a class of muscle without which human beings couldn't survive. There are over 50 different sphincters in the human body. How many can you name?
Leonard: I was wrong. This is exactly like Knight Rider.

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.

Penny: The Flash shirt is what? Because you're gonna run really fast?
Sheldon: No, the Flash shirt is because it's Friday. But it's nice when things work out.

Sheldon: At my age, do you know how I'm statistically most likely to die?
Leonard: At the hands of your room mate?
Sheldon: An accident.
Leonard: That's how I'm going to make it look.

Penny: You wanna turn yourself into some sort of robot?
Sheldon: Essentially, yes.
Penny: Okay, here's my question: Didn't you already do that?