Sheldon: While we live in a deterministic universe, you do have free will. Now sit down.

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.

Leonard: I'm not going out tonight, Raj.
Raj: All right. Would you mind if I went to your room and downloaded some Asian pornography?
Leonard: Very much.
Raj: Doesn't have to be Asian.

Wolowitz: At least I can talk to women without being drunk.
Rajesh: Excuse me, I have selective mutism, a recognised medical disorder. You're just a douche.

*Raj comes in playing Darth Vader's background music from Star Wars*
Leonard: Would you please turn your shirt off?
Raj: What? I'm giving myself dramatic entrance music. People will know I'm awesome and to be feared.
Wolowitz: Right. There's nothing more awesome and frightening than a man who's got music blasting from between his nipples.

Wil Wheaton: You ready to bowl?
Sheldon: Oh, I'm ready. I don't know if Stuart told you what you are up against tonight, but before you stands the co-captain of the East Texas Christian Youth Holy Roller Bowling League Championship Team 7-12 year-old division. Also, Penny is pretty good.
Wheaton: Great, then it's on.
Sheldon (to himself): Foolish Wil Wheaton. It was never off.

Sheldon: I don't know which arctic expedition you guys were on, but I thought it was a hoot and a half.

Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Dr. Plimpton: Tonight, you are the delivery man, you brought soup, and uh-oh! Raj and I don't have enough money to pay you! So we'll have to come to some other kind of arrangement?
Howard: Beg your pardon?
Dr. Plimpton: You two figure out the details; I'm gonna change into something I don't mind getting ripped off my milky flesh! (goes off to change)
Howard: What the frack?
Raj: Go away. She wants New Delhi, not kosher deli. Besides, you have a girlfriend.
Howard: Yeah, we broke up weeks ago.
Raj: What? Why didn't you say anything?
Howard: I was waiting for the right time; this is a right time.

Raj: Ha-ha! Eat my dust, racially stereotypical plumber.
Sheldon: That's not fair! I got stuck behind a tree.
Raj: And a cow, and a penguin. Face it dude, whether it's a real car or a virtual car, you can't drive.
Sheldon: Just need a little more practice.
Raj: What you need is cheat codes, motor skills and a genie who grants wishes to little boys who sucks at MarioKart.

Wolowitz: Okay, forget giant ants. How about giant rabbits?
Raj: Big or small, I don't like rabbits. They always look like they're about to say something, but they never do.

Sheldon: I just want you both to know, when I publish my findings, I won't forget your contributions.
Howard: Great.
Sheldon: Of course, I can't mention you in my Nobel acceptance speech. But, when I get around to writing my memoirs, you can expect a very effusive footnote and perhaps a signed copy.

Sheldon: You fellas are planning a party for me, aren't you?
Howard: Okay, Sheldon, sit down.
Sheldon: If there's going to be a theme, I should let you know that I don't care for luau, toga, or under the sea.

Wil Wheaton: I call my meemaw, Nana, and she's going to be very happy to hear my small rock kills your enchanted bunny.

Sheldon: Why did the chicken cross the Mobius Strip? To get to the same side. Bazinga!