Raj: How could you send her away?!
Sheldon: She was late. And she found atomic spectroscopy boring. I wouldn't coitus her with your genitals.

Leonard: Sheldon, I know what you did, now change the password back.
Sheldon: Well, powder me in sugar and call me a donut, if it isn't Leonard Hofstadter.

Sheldon: (Knocking on Penny's door early in the morning). Penny, Penny, Penny!
(Penny opens the door).
Sheldon: Good morning.
Penny: Do you have any idea what time it is?
Sheldon: Of course I do. My watch is linked to the atomic clock in Boulder, Colorado. It's accurate to one-tenth of a second, but as I'm saying this it occurs to me once again your question may have been rhetorical.

Leonard: New neighbor?
Sheldon: Evidently.
Leonard: Significant improvement over the old neighbor.
Sheldon: A 200 pound transvestite with a skin condition, yes, she is.

Raj: You can't wear the hands on the date.
Sheldon: Hulk sad!

Sheldon: You know I'm in such a good mood I'm actually finding your tenuous grasp of the English language folksy and charming today.

Leonard: Sheldon, why is this letter in the trash?
Sheldon: Well, there's always the possibility that a trash can spontaneously formed around the letter, but Occam's Razor would suggest that someone threw it out.

Sheldon: I don't care if anybody gets it. I'm going as the Doppler Effect.

Sheldon: Penny.
Penny: What?
Sheldon: I can't sleep.
Penny: Maybe that's because your hole is still open.

Sheldon: Excuse me. You're misusing the word 'ho'. It's an interjection used to call attention to a destination, not an object, as in 'land ho' or 'westward ho'.

Sheldon: I never joke about safety.

Kurt: You are lucky little dwarf.
Sheldon: He is a hobbit! Don't worry, I've got your back!

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

Leonard: Stuart's kind of interested in Amy.
Sheldon: Well of course he is. She's very interesting. Did you know, when she was 14 she severed the webbing between her own toes?

Sheldon: Chinese Food, Vintage video games. After the nightmare of Anything Can Happen Thursday, this is Friday night the way it was meant to be.
Howard: Who's up for Sheldon-Free Saturday?