You keep in mind that my sharply-worded comments on yelp.com recently took down a muffin store

Sheldon [filling out medical form]: When was your last menstrual period?
Penny: Oh! Next question!
Sheldon: I'll put in progress

I should have asked for much more than a comic book and a robot.

Leonard, when that woman moved in three years ago, I told you not to talk to her, and now look, we're going to be late to the movies.

That seems like an awful lot of trouble to go through for intercourse. Don't you have access to women who will do it for money?

Sheldon: Is that what you're wearing to watch football over at Penny's?
Leonard: What's wrong with a football jersey?
Sheldon: Nothing. That, however, appears to be a football cocktail dress.

If you're interested, I also know all about frying meat that isn't chicken as if it were chicken

Sheldon: I came here to defeat Wil Wheaton: the man who destroyed my dreams, but I can't destroy Wil Wheaton: the man who loved his mee-maw

It might also interest you to know that Wil Wheaton currently ranks sixth on my all-time enemies list, right between director Joel Schumacher, who nearly destroyed the Batman movie franchise, and Billy Sparks, who lived down the street from me and put dog poop on the handles of my bicycle

Raj: No, no, no, no, that rate is much too low for what you'd expect from this collision. Do you understand we're taking about dark matter colliding in outer space?
Sheldon: Yes, of course I understand, and who are you to tell me about outer space?
Raj: Well, I am the astrophysicist! Astro means space!
Sheldon: Astro means star.
Raj: Okay, let me just tell you, if we were having this argument in my native language, I'd be kicking your butt!
Sheldon: English is your native language!

Sheldon: Yes, since their relationship became carnal, Penny has updated his designated term of endearment, distinguishing him from those she calls "sweetie," usually as an attempt to soften a thinly-veiled insult.
Penny: You're boring people, sweetie.
Sheldon: Although sometimes, she omits the veil entirely.

Leonard: I've always been a little confused abut this -- why don't Hindus eat beef?
Raj: We believe cows are gods.
Sheldon: Not technically. In Hinduism cattle are thought to be like gods.
Raj: Do not tell me about my own culture Sheldon! In the mood I'm in I'll take you out, I swear to cow!

TBBT Quotes

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny, get your own Wi-Fi." No spaces.

Sheldon: Why do you have the Chinese character for "soup" tattooed on your right buttock?
Penny: It's not "soup," it's "courage."
Sheldon: No it isn't. But I suppose it does take courage to demonstrate that kind of commitment to soup.
Penny: How'd you see it? You said you wouldn't look.
Sheldon: Sorry. As I told you, the hero always peeks.