Sheldon: I should've brought an umbrella.
Leonard: What for? It's not going to rain.
Sheldon: I know that, but with skin as fair as mine, moon burn is a real possibility.
Howard: That's a bazinga, right?
Sheldon: One of my best, don't you think?

Leonard: Don't worry about the moon. We, we set our laser to stun.
Zack: Smart.
Leonard: Now, we'll be able to see the beam when it leaves, but it won't be strong enough when it comes back to be seen by the naked eye.
Zack: (chuckling) Naked.

Leonard: So, how'd you two guys meet?
Zack: My company designs the menus for the Cheesecake Factory.
Leonard: Your company?
Zack: Well, it's my dad's, but me and my sister are VPs.
Leonard: So, menus?
Zack: I know it sounds easy but there's a lot of science that goes in designing them.

Zack: How can you bounce a laser off the moon if there's no gravity?

Zack: One question. How can you be sure it won't blow up?
Leonard: The laser?
Zack: The moon.

Sheldon: That's not afternoon. That's prevening.
Howard: What?
Sheldon: It's a time of day I invented. It better defines the ambiguous period between afternoon and evening. Prevening. I'm fairly certain it will catch on as it fills a desperate need.
Raj: Right, okay. What are you doing tomorrow prevening?
Sheldon: Well, tomorrow's Saturday. Saturday night is laundry night, so I'll be spending the prevening pre-sorting and pre-soaking.

Penny: Damn you, you rat bastard! In the olden days, I never would have known he was that stupid.

Wolowitz: Good God, what have we done?

Leonard: Dr. Cooper?
Louis: No, you want the crazy guy next door.

Sheldon: What's the sixth noble gas?
Leonard: Uh, radon?
Sheldon: Are you asking me or telling me?
Leonard: Telling you?
(Sheldon gives Leonard a stern look)
Leonard: Telling you.

Sheldon: I assure you, you'll be sorry that you wasted your money on an iPod when Microsoft comes out with theirs.
Rajesh: Do you have an opinion about everything?
Sheldon: Yes.
Howard: And you just assume you're right?
Sheldon: It's not an assumption.

Sheldon: Cathedra mea, regulae meae. That's Latin for my chair, my rules.

Sheldon: Roommates agree that Friday nights shall be reserved for watching Joss Whedon's brilliant new series Firefly.
Leonard: Does that really need to be in the agreement?
Sheldon: We might as well settle it now, it's going to be on for years.

Penny: Okay, Babydoll Pink, let's see if you can cover up the fact that I got my dad's feet.

Leonard: Not only that Sheldon saved my life, but that he didn't report me to the landlord, or the police, or homeland security.