Sheldon: Eat one of your Luna bars. Very often when women think they're angry, they're really just hungry.

Sheldon: You may not realize it, but I have difficulty navigating certain aspects of daily life. You know, understanding sarcasm, feigning interest in others, not talking about trains as much as I want. It's exhausting!

Sheldon: (Playing hackey sack) One, two, three, four, five, six, seven, eight. Drat. I'm never going to get to forty-three again. One, two, three, four. Rats.

Sheldon: Remarkable. Diamonds. Crystalized carbon. Every day, people go to the grocery store and come home with sacks full of carbon, in the form of charcoal brickets, which they toss in their barbecues and set on fire. But just because you have some carbon with the atoms stacked neatly, you expect me to plunk down thousands of dollars.

Sheldon: Leonard, the transformers teach us that things are not always what they appear to be. You know, like, a semi truck might be an alien robot, or someone in a romantic relationship might feel differently than they appear to.

Sheldon: Ooh, now that is a treat that's hard to beat. Get the Mad Hatter on the horn. I'm having a tea party!

Sheldon: *knock knock knock* Wil Wheaton!
*knock knock knock* Wil Wheaton!
Wait, how many was that?

Howard: Okay, here it is. Bernadette said you guys are all sick of me talking about my trip to space. Is that true?
Sheldon: Yes.
Raj: No.
Sheldon: We seem to have different approaches here. I was going for helpful honesty. I have no idea what you're doing.
Raj: It's called being nice.
Sheldon: Okay. If you think being nice will get him to shut up, I'll try it.

Sheldon: I'll be Coop and he'll be Wheels. If he's okay with that.

Sheldon: Steven Hawking's a genius and he talks like a robot. It's everything I ever wanted in a friend.

Stephen Hawking: What does Sheldon Cooper and a black hole have in common? They both suck.

Stuart: Hey. Hey, look at you guys!
Amy: I'm Raggedy Ann, and he's Raggedy C-3PO.
Sheldon: It was a compromise. I lost.

Sheldon: All games are made up. They're not found in nature. You don't just dig in the ground, and come across a rich vein of Rock'em Sock'em Robots.

Sheldon: The word is Polish. See, look.
Polish sausage. And the model of the solar system developed by Nicolaus Copernicus, a Polish astronomer. And then, finally, if that wasn't enough, which it should've been, this is Madame Curie killing herself by discovering radium, who, although she was a naturalized French citizen, was Polish by birth.
Penny: Excuse me, the word is polish. See? Small p.
Sheldon: Ah! So it is. I guess we both share blame on this one.

Leonard: In what universe is that a present?
Sheldon: It's not a present, it's the present. Look. There's you and me. It's Penny and Amy. We're playing Pictionary. In the present.
Penny: Oh, my God, we're gonna kill them.