Amy: Why do you smell like smoke?
Sheldon: I was in Vegas.
Amy: Vegas?
Sheldon: I'm sorry. Las Vegas.

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: Wow! You look beautiful.
Amy: Really? 'Cause I was gonna return it.
Sheldon: Why would you return it? You look like a pile of swans.

Penny: What if you asked for $20 million?
Sheldon: I'm sorry, I'm trying to do science, not hire Lady Gaga to come to my birthday.
Penny: Do you even know who Lady Gaga is?
Sheldon: Presumably, the wife of Lord Gaga.

Sheldon: This is it.
Pit Boss: Is everything okay, sir?
Sheldon: Oh. Hi. It's better than okay. I am a physicist, and I have been observing this wheel for hours and running a chi-square analysis, which is how I know that the ball is far more likely to land on 32, 17 or five. So if you could hold off on replacing this wheel, I'd like to make several large bets.
Pit Boss: Well, good for you. Pelican.
Sheldon: What's pelican?
Pit Boss: Sir, would you come with us?
Sheldon: Oh, no. I have to place my bet first. This is for science. [carried away by security]
Croupier: 17 black.
Sheldon: No! No!