Don't worry about the moon. We set our laser to "stun."

Leonard

Sheldon: I should have brought an umbrella.
Leonard: What for? It's not gonna rain.
Sheldon: I know that, but with skin as fair as mine, moon burn is a real possibility.

Sheldon: Are you asking me or telling me?
Leonard: Telling you?

Sheldon: That's not an apology; that's simply an acknowledgment that I was right.
Leonard: Okay, I'm sorry.
Sheldon: There you go.

Leonard: Is that your dad?
Wolowitz: If she grows any more hair on her face, yes.

I assure you, you'll be sorry you wasted your money on an iPod when Microsoft comes out with theirs.

Sheldon

Leonard: What am I doing in your spam folder?
Sheldon: I put you there after you forwarded me a picture of a cat playing the piano entitled, "this is funny."

Sheldon: Roommates agree that Friday nights shall be reserved for watching Joss Whedon's brilliant new series, "Firefly."
Leonard: Does that really need to be in the agreement?
Sheldon: Might as well settle it now; it's going to be on for years.

Wheaton: Embrace the Dark Side!
Sheldon: That's not even from your franchise!

Can I get you something? A feminine hygiene product or a bowel-regulating yogurt?

Sheldon

Dr. Plimpton, Penny is a waitress who doesn't understand the role gasoline plays in the internal combustion engine.

Sheldon

Go away! She wants New Delhi, not Kosher Deli!

Raj

The Big Bang Theory Season 3 Quotes

A neutron walks into a bar and asks, "How much for a drink?" The bartender says, "For you? No charge."

Sheldon

Sheldon: Why are you crying?
Penny: Because I'm stupid!
Sheldon: Well that's no reason to cry; one cries because one is sad. For example, I cry because others are stupid and it makes me sad.