Penny: I'm not leaving you for Bill Gates.
Leonard: You sure? I bet his Internet's really fast.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Sheldon: You know what they say, fool me "N" times, where "N" equals the amount of times you've already fooled me, shame on you. Fool me "N" plus one times, shame on me.

Leonard: Uh, M-Mr. Gates, I'm-I'm Dr. Leonard Hofstadter. We've actually met before.
Bill Gates : Sorry, I don't remember.
Leonard: You were so nice, a-and it was really special to me because you've been such a big influence on my life. I mean, ever since I was a little kid, I've looked up to you like-like a hero. (sobbing)
Bill Gates : Oh, now I remember. Would you like a tissue?
Leonard: How about a hug?
Bill Gates : How-how about a tissue?

Raj: But why do they still call Batman using the Bat-Signal? Wouldn't it just be, like, easier to text him?
Howard: The Bat-Signal isn't just to alert Batman, it's also to strike fear in the hearts of his enemies and let them know he's coming.
Leonard: Sort of like Sheldon's knock.
Sheldon: Comparing me to Batman? I'll take it.