Penny: Sheldon, would you like to come in?
Sheldon: I suppose I could spare a few minutes. (Looking at Penny's apartment) Were you robbed?
Penny: No.
Sheldon: How can you be sure?

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.

Sheldon: *knock knock knock* Leonard? (x3)
Leonard: What, Sheldon!? What, Sheldon!? What, Sheldon!?
Sheldon: Tell me what you see here.
Leonard: The blunt instrument that will be the focus of my murder trial?

Sheldon: I would ask you to find some way to suppress your libido.
Penny: I could think about you.
Sheldon: Whatever works.

Sheldon: Well, this is very pleasant.
Leonard: I'm glad you're enjoying yourself.
Sheldon: And you said there would never be enough pasta for the three of us.