Sheldon: It's a bust of Sir Isaac Newton.
Penny: Oh sure, sure. Very Christmasy.
Sheldon: Well, excuse me, it's much more Christmasy than anything you put on the tree.
Leonard: Here we go...
Sheldon: December 25th, 1642. Julian calendar. Sir Issac Newton is born. Jesus, however, was actually born in the summer. His birthday was moved to coincide with the traditional pagan holiday that celebrates the winter solstice with lit fires and slaughtered guts, which frankly sounds like more fun than twelve hours of Church with my mother, followed by fruit cake.

Leonard: The more the merrier.
Sheldon: That's a false equivalency, more does not equal merry. If there were two thousand people in this apartment, would we be celebrating? No, we'd be suffocating.

Wolowitz: In romance, like show business, always leave them wanting more.
Leonard: What does that mean?
Penny: He struck out.

Wolowitz: Before you and Penny hooked up, did she ask for any sort of commitment?
Leonard: No, she was pretty clear about wanting to keep her options open.

Leonard: The meteors are so pretty.
Raj: With your American accent, everything you say sounds stupid.

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.

Wolowitz: Sheldon knows football?
Leonard: Apparently.
Wolowitz: I mean, Quidditch, sure. But football?

Raj: The only thing I've learned in the last two hours is that American men love drinking beer, pee too often, and have trouble getting erections.
Leonard: Focus on the game, not the commercials, Raj.
Raj: I'm just saying, maybe if you people cut back on the beer, you could get out of the bathroom and satisfy your women without pharmaceutical help.

Leonard: You know deep down on the inside, Howard's a good guy
Penny: The problem isn't what's on the inside, it's the creepy candy coating

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!

Sheldon: Leonard, you can't train my girlfriend like a lab rat
Leonard: Actually, it turns out I can
Sheldon: Well you shouldn't

Leonard: Why would you buy peppermint schnapps?
Penny: Because I like peppermint, and it's fun to say schnapps!

TBBT Quotes

Penny: Here's a question-- as an alien pretending to be human, are you planning to engage in any post-prom mating rituals with Amy?
Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.
Sheldon: Well, if it's part of the prom experience, then I'm open to it.
Penny: You're kidding.
Sheldon: I may be an alien, but I have urges.If Amy wants to copulate by firing her eggs into space, well, then, I will happily catch them with the reproductive sac on my upper flermin. I'm not the best at reading facial cues, but I can see that you're a little turned on.

Penny, there's only one cookie with something in the middle that solves life's problems, and that's an Oreo. Or a Nutter Butter, if you're in a pinch.

Sheldon