Leonard: You're going march yourself over there right now and apologize.
Sheldon: Pfffft.
Leonard: What's funny?
Sheldon: That wasn't sarcasm?
Leonard: No!
Sheldon: Oh. Boy, you are all over the place this morning.

Sheldon: Where exactly does the half-sandwich come from? Are you giving me half of someone else's sandwich, or do I have to wait for someone in the restaurant to order the other half?

Sheldon: I have a masters and two PhDs. I should not have to do this.

Leonard: Sheldon. Don't make that noise, it's disrespectful.
Sheldon: I should hope so. It was a snort of derision.

Penny: Hey Sheldon, whattcha got there a new comic book?
Sheldon: Old comic book. I just got it from the safe deposit box.
Penny: What do you have a safe deposit box for?
Sheldon: Old comic books.

Sheldon: I was otherwise engaged.
Penny: Doing what?
Sheldon: I was examining perturbutive amplitudes in N=4 supersymeteric theories leading to a re-examination of the ultraviolet properties of multiloop N=8 supergravity using modern twistor theory.

Leonard: Come on, you need a four-person team. We're four people
Sheldon: By that reasoning we should also play bridge, hold up a huppah and enter the Olympic bobsled competition.

Sheldon: Now to the astronomers in the audience, get ready to see the dark side of the moon. Now here's Uranus!

Leonard: What's going on?
Sheldon: We scored. I'm the wingman.

Sheldon: Oh, Ubuntu. You're my favorite Linux-based operating system.

Sheldon: You want me to use my intelligence in a tawdry competition? Would you ask Picasso to play Pictionary? Would you ask Noah Webster to play Boggle? Would you ask Jacques Cousteau to play Go Fish?

Sheldon: Eat this slice of cheese without farting and you can sleep with my sister.

Sheldon: I'll watch the last 24 minutes of Doctor Who, although at this point it's more like Doctor Why Bother.

Sheldon's computer: We are out of herbal tea. Do you have any?
Penny: Okay, let me check.
Sheldon's computer: Some hiney would be nice.
Penny: Hiney?
Sheldon's computer: Honey.

Leonard: How could you just sit there and let them spy on me?
Sheldon: They were very smart. They used my complete lack of interest in what you are doing.