Sheldon: My credibility may have been damaged.
Barry Kripke: Completely wrecked.

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

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!

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: 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?

Sheldon: But evolution is not opinion, it's a fact.
Mary Cooper: And that is your opinion.
Sheldon: [to Leonard, Howard and Raj] I forgive you, let's go home.