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.
Penny: I always tear up when the Grinch's heart grows three sizes.
Sheldon: Tears seem appropriate. Enlargement of the heart muscle, or hypertrophic cardiomyopathy, is a serious disease which can lead to congestive heart failure.
That's all I know. Oh, wait! Fig Newtons were named after a town in Massachusetts, not the scientist.
Penny: Is that why they're called Fig Newtons?
Sheldon: No. Fig Newtons are named after a small town in Massachusetts. No, don't write that down!
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.
Sheldon: Where's your notebook?
Penny: I don't have one.
Sheldon: How are you gonna take notes without a notebook?
Penny: I have to take notes?
Sheldon: How else are you gonna study for the tests?
Penny: There's gonna be a test?
Sheldon: Tests. Here, it's college ruled, I hope that's not too intimidating.
Wolowitz: In romance, like show business, always leave them wanting more.
Leonard: What does that mean?
Penny: He struck out.
Wolowitz [about Bernadette]: She wants a commitment, but I'm not sure if she's my type.
Penny: She agreed to go out with you for free. What more do you need?
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.
Sheldon [filling out medical form]: When was your last menstrual period?
Penny: Oh! Next question!
Sheldon: I'll put in progress
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