Howard: Sheldon, why are you arguing with the DMV?
Sheldon: How else are they going to learn? Look, question 2, "When are roadways most slippery?" Now, okay, there are three answers, none of which are correct. The correct answer is, when covered by a film of liquid sufficient to reduce the coefficient of static friction between the tire and the road to essentially zero, but not so deep as to introduce a new source of friction.

DMV Worker: Application?
Sheldon: I'm actually more of a theorist.
Howard: The application in your hand, give it to her.
Sheldon: Oh.

Leonard: Sheldon, I told you, I only have access to the free-electron laser at night. I can't drive you for the next few weeks.
Sheldon: No, you said you couldn't drive me to work, this is from work.
Leonard: Howard, help me out here.
Howard: No, just for the fun of it, I'm gonna take his side.
Sheldon: Now, how do you propose I get home?
Leonard: How did you get here in the first place?
Sheldon: Penny. But I sense that's no longer an option.
Leonard: Look, I need to get to the laser lab, you're just going to have to find someone else to take you home. [Sheldon looks to Howard]
Howard: Oh damn, I picked the wrong side.

Penny: (pulling car over) Get out.
Sheldon: Well, I have to tell you that while I do have a theoretical understanding of the workings of an internal combustion engine, I'm not sure I'm capable of performing diagnostics.
Penny: I said, get out.
Sheldon: Okay. I'll give it a shot. (Penny drives away)

Sheldon: Where are you going?
Raj: I'm taking you home.
Sheldon: Oh, but I'm not going home. It's Wednesday. Wednesday is new comic book day. We have to go to the comic book store. And then we have to stop at Soup Plantation, it's creamy tomato soup day, and Radio Shack, there's a sale on triple-a batteries. Plus, we have to go to Pottery Barn and return my Star Wars sheets.
Raj: I have a better idea.
Sheldon: You want to go to Pottery Barn first?

Raj: Why did Howard leave you in the middle of the road anyway?
Sheldon: We had a difference of opinion.
Raj: Over what?
Sheldon: Whether or not he was trying to kill me. For the record, I maintain he was.

Sheldon: Oh, Leonard, there you are, I'm ready to go home.
Leonard: I just got here.
Sheldon: Good, perfect timing.

Penny: Honey, you'll be fine as long as you don't do that bungee cord thing, okay?
Sheldon: Penny, didn't you recently state that you and I are friends?
Penny: Yes, Sheldon, we are friends.
Sheldon: Then I hereby invoke what I'm given to understand is an integral part of the implied covenant of friendship. The favor.
Penny: Oh, dear God.
Sheldon: I'm sorry. I didn't realize I was interrupting your morning prayers. When you're done, we'll go.

Sheldon: Okay. I'll say an element, and uh, you say an element whose name starts with the last letter of the one I said, okay? I'll start. Helium. Now, you could say Mercury. That would give me a Y. Ooh, very clever, that's a tough one. So I go Ytterbium, which gets you back to M. So you go Molybdenum, and I say Magnesium, you say Manganese, and I say Europium, and, and you're left with Mendelevium, and there are no more M's because I believe that Meitnerium should still be called Ekairidium, so congratulations, you win. Do you wanna go again?

Sheldon: Here’s a fun question. Do you know what the most common street name is?
Penny: No.
Sheldon: The answer's tricky. It's Second Street. You see, you'd think it would be First Street, but in most towns, First Street eventually gets renamed to something else, you know, like Main Street, Broad Street, Michigan Avenue.

Sheldon: You're going up Euclid Avenue?
Penny: Mm-hmm.
Sheldon: Leonard takes Los Robles Avenue.
Penny: Well, good for Leonard.
Sheldon: Euclid Avenue is shorter as the crow flies, but it has speed bumps, which appreciably increase point-to-point drive time, making it the less efficient choice. But you have the conn. Of course, if you're not going to slow down for the speed bumps, I withdraw my previous objection.

Sheldon: Thank you for driving me to work.
Penny: You know this is my day off, Sheldon.
Sheldon: Oh, good. I'm not keeping you from anything.

Sheldon: So what do you think, Howard? It's not that bad, right?
Howard: A little electrical tape, some solder ... Are you insane? I've seen space probes that crashed into the desert that were in better shape than this.

Sheldon: Leonard, this is Tom.
Leonard: Hi, Tom. Sheldon? Didn't I explain to you about your little mistake in the cafeteria?
Sheldon: Yes, you were very clear. As was everyone else at the table. Tom, however, has been chosen by science as a suitable mate for Penny.

Sheldon: Anyhow, on a scale of 1 to 5, with 1 being always initiated by him, and 5 being always initiated by you, how do you prefer your sexual encounters to begin?
Penny: That's on the registration?
Sheldon: Oh yes, it's quite extensive. But if we complete it, we get a free expansion pack: 75 additional quests.
Penny: Ooh, awesome. Okay, I totally like to initiate, I'm a big old five.
Sheldon: Good to know. Big ol' five.