Wil Wheaton: I tell you, this business is brutal. To this day I hate going on auditions. I walk in and I can just feel them thinking "He was such a cute kid. What happened to him"? Then I don't get the job and I can never find out why. Honestly, I get so depressed there are entire weeks where I can't even get out of bed.
Leonard: Okay, this was helpful!

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.

Bernadette: I like the Wii.
Sheldon: Thanks, Grandma.

Sheldon: Oh look, a quarter!

Sheldon: Boy, do I have to urinate.
Leonard: If only there were a solution to that.