Sheldon: Well, you can add Jerry's Junction to the list of train stores Sheldon Cooper will never set foot in again.
Leonard: Rough night, Casey Jones?
Sheldon: You don't know the half of it. It was billed as a lively give-and-take on the merits of model train sizes. But it was actually a set-up to intimidate weak-minded spineless rubes into buying H-O starter sets.
Leonard: What's in the bag?
Sheldon: I don't want to talk about it. But it's not a spine,I'll tell you that.

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: The only person who signed my yearbook was my mother. "Dear Amy, self respect and a hymen are far better than friends and fun. Love, mom."

Bernadette: Good Morning, handsome.
Howard: Good morning, mom.
Bernadette: It's me!

Amy: I have a sorta kinda boyfriend at home playing with a model train, but you don't hear me bitching about it.