Leonard: Sheldon. Don't make that noise, it's disrespectful.
Sheldon: I should hope so. It was a snort of derision.

Sheldon: Oh, but don't worry. I won't do that to you.
Amy: Maybe you should.
Sheldon: What?
Amy: This has been your lifelong dream. And you may not get another chance. I don't want to be the reason that you don't win a Nobel.
Sheldon: You're the only reason I deserve one.

Sheldon: Uh, but this is violating university code.
Leonard: A little, but if I may quote Einstein, "The pursuit of science calls us to ignore the rules set by man"
Sheldon: Huh. All right, do it. Tell him we're in.
Leonard: Done.
Sheldon: I can't find that quote on the Internet. Did you make that up?
Leonard: Before I answer, may I just say your skin has never looked better.
Sheldon: Aren't you just made of sugar.

Sheldon: How will Raj ever reach true greatness if his friends lower the bar for him? When I was eleven, my sister bought our father a "world's greatest dad" coffee mug, and frankly the man coasted until the day he died.

Sheldon: *knock knock knock* Amy. *knock knock knock* Amy. *knock knock knock* Amy.
[Amy opens the door. Sheldon is on one knee, holding out an engagement ring]
Sheldon: Will you marry me?

Leonard: Wanna catch me up?
Sheldon: Well, let's see. She attempted to open her apartment with her car key because her face is overly Midwestern. She hasn't had sex in 6 months, and she ate a fly.
Leonard: Uh-huh. Seriously, 6 months?

Sheldon: Would you like me to bring you some warm milk?
Leonard: I'm lactose intolerant.
Sheldon: And you don't wish to alarm me with any more loud noises. Very thoughtful.

Sheldon: Enjoy the neurobiology conference.
Amy: I will. I wish you were here.
Sheldon: At a neurobiology conference? What a mean thing to say.
Amy: Okay, I'm glad you're not here?
Sheldon: Aww, you always know just what to say after I tell you what to say.

Sheldon: Sheldor, back online.
Penny: What's AFK?
Sheldon: AFK. Away from keyboard.
Penny: Oh, I see.
Sheldon: What does that stand for?
Penny: "Oh, I see"?
Sheldon: Yes, but what does it stand for?

Sheldon: To really understand the story here, we need to start at the very beginning. A small town in East Texas where a young genuis named -
Leonard: - Sheldon!
Sheldon: Yes, that's right, Sheldon Cooper. He was bitten by his neighbor's dog, leading to his first scientific break through: the Doggy Death Ray. Which sadly he couldn't build because Santa wouldn't bring him enriched uranium.

Sheldon: See, as you know, a few years ago I achieve one of my lesser dreams and became a notary public. Well, from time to time, I notarize banking documents for Raj. The Koothrappalis aren't just rich. They're Richie Rich rich.
Penny: Well, so how much is that?
Sheldon: About halfway between Bruce Wayne and Scrooge McDuck.

Leonard: What kind of a person steals another person's car in broad daylight?
Sheldon: What kind of person leaves his keys in the car?
Leonard: I thought we agreed this was all Koothrappali's fault.
Sheldon: You're right. (To Raj) Nice going.

Sheldon: That's an inexact parallel. You and Leonard can always return to being friends, whereas I can never return to a state in which Wolowitz has not bested me like Mrs. Riley's chicken.
Penny: What's Mrs. Riley's chicken?
Sheldon: A chicken that was owned by Mrs. Riley.
Penny: Okay, forget the chicken.
Sheldon: Well, I wish I could.

Sheldon: All right, pick a card.
Howard: Okay.
Sheldon: Bippity-boppity-boo.
Howard: What's with the wand and the beep?
Sheldon: The wand is called showmanship, and the beep is none of your business. Oh, excuse me, I'm getting a text message completely unrelated to this magic trick. Oh, look, my dry cleaning's ready. And your card was the five of spades. Ta-da.
Raj: These cards have bar-codes on them. The wand is a reader. It's transmitting to your phone.
Sheldon: I said, ta-da. Show's over.

Alex: Is there a problem?
Sheldon: Let's not call it a problem. Let's call it an opportunity. To solve a serious problem.