Sheldon: It's doubtful that his mother will be over-impressed with a woman whose biggest achievement was memorizing the Cheesecake Factory menu.
Penny: Hey, it's a big menu! There's two pages just for desserts!
Leonard: And those specials, they change every day!
Penny: Okay, it's lame when I say it, it's just ridiculous when you pile it on.

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

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.