Penny: Aw. When he says things like that, I just want to hug him and make everything better.
Leonard: My brother was mean to me, too. Yeah, you probably had it coming.

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.

Wil Wheaton: Hey, Sheldon. This is Adam Nimoy.
Adam Nimoy: Nice to meet you.
Sheldon: Oh, it's nice to meet you. I admire your father's work very much.
It's not every day I get to meet someone whose life's journey began in my hero's scrotum.

Howard: May I say something?
Bernadette: Is it about how I can't have new wallpaper 'cause your dad left when you were little and your mom died?
Howard: Never mind.

Sheldon: As a child, when faced with a dilemma, my mother encouraged me to ask, "€œWhat would Jesus do?" The answer to that was always, "Love thy neighbor." But my neighbor had a dead tooth, so that wasn't going to happen.
But that's why I changed it to, "€œWhat would Spock do?"
Adam Nimoy: Did you find that helpful?
Sheldon: Yes. Oh, for example, three years ago when I discovered Penny was eating all my Pop-Tarts, instead of getting angry or vindictive, you know, I got a floor safe.
Penny: I knew I could smell 'em.