Sheldon: Penny, while I subscribe to the "Many Worlds" theory which posits the existence of an infinite number of Sheldons in an infinite number of universes, I assure you that in none of them am I dancing.
Penny: Are you fun in any of them?
Sheldon: The math would suggest that in a few I'm a clown made of candy. But I don't dance.

Leonard: They're gonna get beaten up at that club.
Penny: They're gonna get beaten up at Walgreens.

Sheldon: This alcohol is not working, I still feel dizzy.
Penny: Here, try this one.

Sheldon: Why did the chicken cross the Mobius Strip? To get to the same side. Bazinga!

Sheldon: Oh Lord, this can't be more humiliating.
Leonard: No, no, no, give him a minute.

Sheldon: A neutron walks into a bar and asks how much for a drink. The bartender replies "for you, no charge".

Sheldon: Question: Where are my Pants?

Sheldon: Where are my pants?
Leonard: You might wanna check out YouTube.

Wolowitz: Well no, you're mistaken. You give speeches all the time. What you can't do is shut up.

Sheldon: What self-important preening fraud are they honoring this year?
Leonard: I'm so glad you asked it like that. You!

Sheldon: Hello, I know you're out there. I can hear you metabolizing oxygen and expelling carbon dioxide.

Sheldon: Hello, Kripke. This classic prank comes to you from the malevolent mind of Sheldon Cooper. If you would like to see the look on your stupid face, this video is being instantly uploaded to YouTube. Oh, and a hat tip to Leonard Hofstadter and Raj Koothrappali for their support and encouragement in this enterprise.

Penny: I think I caught the flu. *Throwing up*. Or the plague!

Penny: Who's Adam West?
Sheldon: Who's Adam West!? Leonard, what do the two of you talk about after the coitus?

Howard: Oh, my God. An Alf doll. When I was 11 my mother got me one to help me sleep after my dad left. I used to pretend that my dad had moved to the planet Melmac, and Alf was going to bring him back to me. But he never did. Where's my daddy, puppet? Where is he?