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.

Sheldon: (To his spot) Hello, old friend, Daddy's home.

Sheldon: Fellow warriors, this is Sheldor the Conqueror. We are about to enter Atzel's fortress. Now, this is a long run, so let's do another bladder check. All right, Barry, we'll wait for you again, but you really should see a doctor.

Sheldon: Just when I think I've gotten the hang of sarcasm.

Sheldon: You're in my bedroom.
Penny: Yeah, Leonard gave me an emergency key.
Sheldon: People can't be in my bedroom.

Penny: Can we go talk in the living room?
Sheldon: I'm not wearing pajama bottoms.
Penny: Why not?
Sheldon: I spilled grape juice.
Penny: Well, wear different pajamas.
Sheldon: I can't wear different pajamas. These are my Monday pajamas.

Sheldon: We're gonna have to stop at Pottery Barn on our way to work. I bought these Star Wars sheets, but they turned out to be much too stimulating to be compatible with a good night's sleep. I don't like the way Darth Vader stares at me.

Sheldon: Just because your career's been stagnant for a few years, that's no reason to give up.

Leonard: Didn't I tell you I'd be working nights and you'd have to make others arrangements?
Sheldon: You did.
Leonard: And?
Sheldon: I didn't.

Sheldon: How am I gonna get to work.
Leonard: Take the bus.
Sheldon: But I can't take the bus. They don't have seat belts. And they won't let you latch yourself to the seat with bungee chords.
Leonard: You tried to latch yourself to the seat with bungee chords?
Sheldon: I didn't try, I succeeded. For some reason, it alarmed the other passengers and I was asked to de-bus.

Sheldon: Your check-engine light is on.
Penny: Uh huh.
Sheldon: Typically, that's an indicator to, you know, check your engine.
Penny: It's fine. It's been on for like a month.
Sheldon: Well, actually that would be all the more reason to, you know, check your engine.
Penny: Sheldon, it's fine.
Sheldon: If it were fine, the light wouldn't be on. That's why the manufacturer installed that light, to let you know it's not fine.
Penny: Maybe the light's broken.
Sheldon: Is there a check-the-check-engine-light light?

Sheldon: Looking out at your fresh young faces, I remember when I too was deciding my academic future as a lowly graduate student. Of course, I was 14 and had already achieved more than you could ever hope to, despite my 9:00 bedtime. Now, there may be one or two of you in this room who has what it takes to succeed in theoretical physics. It's more likely that you will spend your careers teaching fifth graders how to make paper-mache volcanoes with baking-soda lava.
Leonard: Oh, good God.
Sheldon: In short, anyone who told you that you would someday be able to make any significant contribution to physics played a cruel trick on you. A cruel trick indeed. Any questions? Of course not. I weep for the future of science. Now, if you'll excuse me, the latest issue of Batman is out. Come, Leonard.
Leonard: Laser demonstration's looking pretty good now, huh?

Sheldon: Oh God, not Euclid Avenue!

DMV Worker: Here's your learner's permit. Go away.
Sheldon: But I'm not done. I have many additional concerns about these questions.
DMV Worker: Don't make me climb over this counter!