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: (Practising speaking Mandarin) Show me your citrus peels.
Penny: Sheldon?
*Sheldon freaks out in Chinese.*
Penny: I'm sorry. Look, do you have a second?
Sheldon: A second what? Pair of underwear?

Kripke: Well, as long as we're here, I might as well take a leak.
Sheldon: Kripke, you're in my spot.

Sheldon: Score 1 for liquor and poor judgement.

Leonard: Sheldon lives in fear of the three-tined forks.
Sheldon: Three tines is not a fork. Three tines is a trident. Forks are for eating, tridents are for ruling the seven seas.

Amy: Kiss me where I've never been kissed before?
Sheldon: You mean like Salt Lake City?

Penny: Okay, I got a box, but there's no key in here. Just letters.
Sheldon: That's the wrong box. Put it back.
Penny: Oh, Sheldon, are these letters from your grandmother?
Sheldon: Don't read those letters.
Penny: Oh, look, she calls you Moon Pie. That is so cute.
Sheldon: (shrieking) Put down the letters!

Sheldon: I decided to take your advice and have arranged to go on a date with Amy Farrah Fowler.
Penny: Oh, that's great. Have fun.
Sheldon: Wait, you have to drive me.
Penny: What?
Sheldon: You know I don't drive.
Penny: Well, go ask Leonard.
Sheldon: I did; he said, and I quote: "Ask Penny, it was her cockamamie idea."
Penny: Leonard said "cockamamie"?
Sheldon: Actually, I'm paraphrasing. Having been raised in a Christian household, I'm uncomfortable with the language he used. And to be honest, I'm not entirely comfortable with "cockamamie".

Sheldon: As usual, you're all wrong. The bravest person in the Marvel universe is the doctor that gives Wolverine his prostate exam.
Howard: How about the guy gets a prostate exam from Wolverine?

Sheldon: (knock, knock, knock) Penny!
(knock, knock, knock) Amy!
(knock, knock, knock) Bernadette!

Raj: Come on, a medium-sized asteroid is still an interesting discovery.
Sheldon: I suppose it could end up on a collision course with Earth and destroy life as we know it.
Raj: You dream different than me.

Sheldon: Sherlock Holmes always says when you eliminate the impossible, whatever remains, however improbable, must be the truth. Now, have you tried doing that?
Officer Hernandez: Nope.
Sheldon: Well, maybe you should. There's lots of books called Sherlock Holmes and there's no books called Officer Hernandez.

Sheldon: This will just take a moment, it's on a five and a quarter inch floppy.
Amy: A floppy disk?
Sheldon: Well, I started the list when I was nine.

Amy: You applied for a mission to be a colonist on another planet and couldn't be bothered to tell me?
Sheldon: Would you have approved?
Amy: Of course not.
Sheldon: Well, based on your reaction, it looks like I made the right choice. Isn't that right, Giuseppe.

Penny: Looks like you've been to the Renaissance Fair ... I'm hoping.
Sheldon: Renaissance Fair? More of a medieval-slash-Age of Enlightment-slash-any-excuse-to-wear-a-codpiece fair.