Penny: Where are my clothes?
Sheldon: Your clothes?
Penny: Yes. I left them in the washers and when I went down to get them, they were gone.
Sheldon: Really? Despite the sign that says: "Do not leave laundry unattended?"

Sheldon: You know, I do recall seeing some female undergarments. Where was that? Oh, yes. Earlier this evening, I happened to gaze out the window and a brassiere caught my eye. Do those look familiar?

Sheldon: Alright, Klingons, pencils down.

Penny: This has gotten way out of hand, okay. I've done some stupid things, you've done some stupid things. How about we just call it even, and move on with our lives?
Sheldon: I've done no stupid things.
Penny: Look, you've gotta meet me halfway here.
Sheldon: I am meeting you halfway. I'm willing to concede that you've done some stupid things.

Sheldon: Hi, Mom, how are you?But, Mom, she keeps sitting in my spot. And she touched my food. Okay, yes, I took her clothes, but she started it. (throwing a fit) No, that's not fair. Why should I have to apologize? I really don't think this is the kind of thing Jesus concerns himself with. No, you're right. I don't really know what Jesus thinks about. All right! Goodbye. (hangs up) (to Leonard) Did you tell on me?
Leonard: Are you kidding me? I already have 2 strikes

Penny: Get them down!
Sheldon: Apologize.
Penny: Never.
Sheldon: Then you just get a very long stick and play panty pinata!

Sheldon: Then I suggest you get them down with a long stick and play panty piata.

Sheldon: I am very, very sorry for what I have done. Here's your laundry, I rescind your strikes and you are no longer banished.

Ramona: You are so witty.
Sheldon: Aren't I?

Sheldon: Who's Nowitzki?
Ramona: I'm Nowitzki.
Sheldon: Oh, so you want me to share credit with you?
Ramona: Uh huh.
Sheldon: Get out!

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?

Leonard: Sheldon lives in fear of the three-tined forks.
Sheldon: Three tines is not a fork. Three tines is a trident. Forks are for eating, tridents are for ruling the seven seas.

Ramona: Didn't a great man once say, "Science demands nothing less than the fervent and unconditional dedication of our entire lives."?
Sheldon: He did.
Ramona: And who was that great man?
Sheldon: Me. Sorry, Leonard.
Leonard: Seriously? You're not coming?
Sheldon: You heard her. How can I argue with me?

Sheldon: (To Penny) Apparently, I'm in some kind of relationship, and, well, you seem to be an expert at ending them.
Penny: Excuse me?
Sheldon: I see man after man leaving this apartment never to return.
Penny: Okay, first of all, it is not man after man.

Leslie: So, dumbass, I heard you made a grad student throw up last night.
Sheldon: The truth can indeed be a finger down the throat of those unprepared to hear it. But why should I cater to second-rate minds?