Penny: Okay, so Kim, the night manager, went on maternity leave, and her husband's name is Sandy, right? So get this, her replacement is a woman named Sandy whose husband's name is Kim.
Leonard: Wow!
Penny: I know. What are the odds?
Sheldon: Easily calculable. We begin by identifying the set of married couples with unisex names. We then eliminate those unqualified for restaurant work: the aged, the imprisoned and the limbless, for example. Next we look at-
Leonard: Sheldon! It's an amazing coincidence, can we leave it at that?
Sheldon: I'm sorry. Ooh, Penny, it's as if the Cheesecake Factory is run by witches.

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: I give up. He's impossible.
Sheldon: I can't be impossible; I exist. I think what you meant to say is, 'I give up; he's improbable'.

Sheldon: You know, I've always wanted to go to a goth nightclub.
Howard: Really?
Sheldon: Bazinga! You never see any of my practical jokes coming, do you?

Leonard: I'm just saying, you catch more flies with honey than with vinegar.
Sheldon: You catch even more with manure, what's your point?