Penny: Oh, big deal. Not knowing is part of the fun.
Sheldon: "Not knowing is part of the fun." Was that the motto of your community college?

Sheldon: I made tea.
Leonard: I don't want tea.
Sheldon: I didn't make tea for you. This is my tea.
Leonard: Then why are you telling me?
Sheldon: It's a conversation starter.
Leonard: That's a lousy conversation starter.
Sheldon: Oh, is it? We're conversing. Checkmate.

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: Can I respond now?
Leonard: Do it.
Sheldon: You mess with the bull, you get the horns. I'm about to show this guy just how horny I can be.
Leonard: Somebody else do it.

Sheldon: I'm exceedingly smart. I graduated college at fourteen. While my brother was getting an STD, I was getting a Ph.D. Penicillin can't take this away.

Mike: I don't know what's scarier: the bathroom clowns or the woman that put them there?
Sheldon: All I know is you can only fit one of her in a car.
*Howard walks in*
Sheldon: And there's the clown that came out of her!

Amy: It says here you can get an annulment if any of the following conditions were met: Were you unable to consummate the marriage?
Sheldon: Penny!? Ha! Next ...

Sheldon: (Typing into a search engine) How do I get 12-year-old schoolgirls excited?
Howard and Leonard: No!

Zack: You know, I saw this great thing on the Discovery Channel. Turns out if you kill a starfish it'll just come back to life.
Sheldon: Was the starfish wearing boxer shorts? Because you might have been watching Nickelodeon.

Penny: So what do you say Sheldon, are we your X-men?
Sheldon: No, the X-men were named for the X in Charles Xavier. Since I am Sheldon Cooper, you will be my C-men.

Sheldon: I'd like to go over some proposed changes to the roommate agreement, specifically to address Penny's annoying personal habits.
Penny: Oh my God! What personal habits?
Sheldon: I have a list. FYI overuse of the phrase "Oh my God" is number 12.

Sheldon: I wouldn't tell you the secret. Sssh!
Leonard: What secret? Tell me the secret.
Sheldon: Mom smokes in the car. Jesus is okay with it, but we can't tell dad.
Leonard: Not that secret, the other secret.
Sheldon: I'm Batman! Ssssh!

Sheldon: This is Leonard. He's your best friend in the world.
Leonard: All right, just stop. This is ridiculous.
Sheldon: Sometimes he gets cranky, but you can trust him with your life. And he does more things for you than I can even begin to list.
Leonard: Thank you.

Sheldon: Oh gravity, thou art a heartless bitch.

Sheldon: Checkmate.
Leonard: Oh, again?
Sheldon: Obviously, you're not suited for three dimensional chess. Perhaps three dimensional Candy Land would be more your speed.
Leonard: Just reset the board!
Sheldon: It must be humbling to suck on so many levels.