Sheldon: All right, are you familiar with the development that resulted from Honore Blanc's 1778 use of interchangeable parts? The assembly line, of course.
Penny: Okay, you know what, if I'm not allowed to be snide, you're not allowed to be condescending.
Sheldon: That wasn't a part of our original agreement, and I do not agree to it now.
Penny: All right, fine. How are we supposed to set up machines and conveyor belts in my apartment?
Sheldon: You're thinking of the moving assembly line, an understandable but not excusable mistake. No, the moving assembly line, that was introduced by Henry Ford in 1908. That innovation is what made possible our modern consumer culture by enabling a low-unit cost for manufactured goods. I guess that isn't one of the topics discussed on your Radiohead.

Sheldon: Really? The only time I'm ever picked first for a team and I'm stuck with the liability?

Amy: Okay, what's the next test?
Sheldon: Loyalty. We need to choose someone who has our backs, someone who will keep our secrets even from each other.
Amy: Well, I don't have any secrets from you. Do you have secrets from me?
Sheldon: Yes. Oh, that has been weighing on me for years.

Sheldon: And worse than that, Edison filmed the first on-screen kiss, so he's basically a pornographer. Although every time I put that in Wikipedia, someone takes it out.

Sheldon: Now to business. Eighteen years ago, I sent the FBI Crime Lab samples from a bag of excrement that had been lit on fire on my front porch for fingerprinting and DNA analysis. Why haven't I heard back yet?
Agent Page: Well, the FBI Crime Lab does have a lot on its plate.
Sheldon: That's of little comfort to a nation attempting to scrape burning faeces off its shoes.

Sheldon: So Bernadette, if I express interest in your baby will you promise not to make me touch it?
Bernadette: Sure.
Sheldon: Hey, how's life with your baby?
Amy: Really? You're never gonna touch their baby?
Sheldon: To this day I've never touched Stuart.

Sheldon: You just lied to Penny.
Leonard: Yes, I did.
Sheldon: And you did it so casually. No rapid breathing, no increase in perspiration.
Leonard: So?
Sheldon: So, lack of physiological response while lying is a characteristic of a violent sociopath.
Leonard: Sheldon, are you worried about your safety?
Sheldon: No. I imagine if you were going to kill me, you'd have done it a long time ago.

Sheldon: You're awfully quiet.
Leonard: Sorry.
Sheldon: No, I like it.
Leonard: Got a lot on my mind.
Sheldon: Would you like to talk about it?
Leonard: Not really.
Sheldon: Grape Nuts for breakfast, quiet car ride, things are really breaking my way today.

Howard: Our culprit is one Mr. Todd Zarnecki, 2711 Ocean View Road, Carlsbad, California.
Sheldon: The name and the address drip with evil.

Leonard: Raj, no, it's a trap. They're flanking us!
Raj: Oooh, he's got me.
Howard: Sheldon, he's got Raj. Use your sleep spell. Sheldon! Sheldon!
Sheldon: I've got the Sword of Azeroth!
Leonard: Forget the sword, Sheldon, help Raj.
Sheldon: There is no more Sheldon. I am the Swordmaster!

Sheldon: It's not the same thing. I don't think you know how I feel at all.
Leonard: Sad?
Sheldon: Hmm, you do get me.

Howard: So, how do you guys want to play this?
Sheldon: Be ruthless. You tell him if he doesn't start talking, we'll register a complaint with his Internet service provider.
Raj: Sheldon, what if he gets his Internet from his cable company? He could lose his HBO and all their delightful original programming.
Sheldon: I don't care! I'm losin' it, man!

Amy: Sheldon, it's the American way, the peaceful transfer of power.
Sheldon: I don't know.
Leonard: Think about Ant-Man.
Sheldon: I'm always thinking about Ant-Man.
Leonard: Michael Douglas had the suit and then he passed it on to Paul Rudd.
Sheldon: Maybe you're right.
Amy: Really? The Ant-Man thing? That's what won you over?
Sheldon: Yes. He got the details right. That's how you use a superhero.

Sheldon: Well, then it looks like we have a winner. Congratulations.
Raj: Well, I should warn you, it's just looking at data for hours and hours on a computer screen.
Sheldon: Uh, stop selling it, kid. You won.

Leonard: How was your day?
Penny: Oh, not good. Still couldn't get in to see Dr. Gallo.
Sheldon: A doctor? Well, I hope you're not contagious. I've got a weekend in the telescope room I've been excited about for almost three minutes.