Wolowitz: Raj, did you ever tell your sister about the time Sheldon got punched by Bill Gates?
Priya: Oh, God, you're kidding.
Raj: No, Gates gave a speech at the university. Sheldon went up to him afterwards and said, "Maybe if you weren't so distracted by sick children in Africa you could have put a little more thought into Windows Vista."
Leonard: Bam, right in the nose. Made me proud to own a PC.

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.

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.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Sheldon: Jacuzzi is a commercial brand, hot tub is the generic term, i.e., all Jacuzzis are hot tubs, but not all hot tubs are Jacuzzis.
Zack: Is that like all thumbs are fingers but not all fingers are thumbs?
Sheldon: Surprisingly, yes.
Zack: Nice! Now what exactly are toes?

Sheldon:He'll be back.
Leonard: (Through the door) Of course, I'll be back, I live here!

Sheldon: Mmm, this is good. Whatever this is.