Barry Kripke: Yeah, but research in to dark energy proved that Einstein's cosmological constant was right all along. So you're still, surprise surprise, a loser.

Barry Kripke: We're all pathetic and creepy, and can't get girls. That's why we fight robots.

Sheldon: No, that's okay. I can fight my own battles. Isn't that right, Bawwy?
Barry Kripke: Is that a reference to my speech impediment? That's pretty hurtful. I can't control it.
Sheldon: You're right. That was uncalled for. I take it back.
Barry Kripke: Of course you do, because you're The Retractor!

Barry Kripke: Yes, yes, yes. He's a jolly good fellow. What time do the strippers arrive?

Howard: Sheldon, you remember the first few weeks we were looking for magnetic monopoles and not finding anything, and you were acting like an obnoxious, giant dictator?
Raj: I thought we were going to be gentle with him.
Howard: That's why I added the '-tator'.

Sheldon: What are they doing here?
Leonard: We came to apologize again and bring you home. So why don't you pack up your stuff, and we'll head back?
Sheldon: No, this is my home now. Thanks to you, my career is over, and I will spend the rest of my life here in Texas trying to teach evolution to creationists.
Mrs. Cooper: You watch your mouth, Shelly. Everyone's entitled to their opinion.
Sheldon: But evolution is not opinion, it's a fact.
Sheldon's mom: And that is your opinion.

Sheldon: Hello Penny. I realize you are currently in the mercy of your primitive biological urges. But, as you have an entire lifetime of poor decisions ahead of you, may I interrupt this one?