You know, I've given the matter some thought, and I think I'd be willing to be a house pet to a race of super-intelligent aliens.

Penny: No, I can't. Sheldon, honey, I don't want things to be weird between us.
Sheldon: Won't it also be 'weird' if I have to say hello to you every morning on my way to work and you're living in a refrigerator box and washing your hair with rainwater?

Penny: Wow, you've got a lot of money in there.
Sheldon: That's why it's guarded by snakes.

Raj: If you don't like this stuff, let's just go next door and build her a bear.
Sheldon: I told you before, bears are terrifying

Sheldon: If I were to give you this gift basket, based on that action alone, and no other data, infer and describe the hypothetical relationship that exists between us.
Employee: Excuse me?
Sheldon: Here. [gives woman gift basket] Now, are we friends, colleagues, lovers? Are you my grandmother?
Employee: I don't understand what you're talking about, and you're making me a little uncomfortable.
Wolowitz: See, sounds just like you and Penny. We'll take it.

Sheldon: I need to know exactly what Leonard did to get you to put an emotional cap in his buttocks.
Penny: What?
Sheldon: Again, urban slang, in which I'm beginning to get remarkable fluency

Penny: Sheldon, what do you want?
Sheldon: I'm certain this will come as no surprise to you, but Leonard is failing in yet another relationship.
Penny: He's having problems with Stephanie?
Sheldon: She's sending virtual livestock to random men on the Internet

It's very simple. Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and—as it always has—rock crushes scissors

I believe the appropriate metaphor here involves a river of excrement and a Native American water vessel without any means of propulsion

I am not going to watch the Clone Wars TV series until I've seen the Clone Wars movie. I prefer to let George Lucas disappoint me in the order he intended

Raj: I'll tell you what, how about we go rock-paper-scissors?
Sheldon: Eww, I don't think so. Anecdotal evidence suggests that in the game of rock-paper-scissors, players familiar with each other tie 75-80% of the time due to the limited number of outcomes. I suggest "rock-paper-scissors-lizard-Spock"

I trusted you with my e-mail address, and you betrayed that trust by sending me Internet banality.

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.

Leonard: Hi. I'm Leonard. You are beautiful. You pop, sparkle and buzz electric. I'm going to pick you up at eight, show you a night you will never forget.
Raj: Where are we going?