Raj: You know what? I think we're both done being disrespected.
Leonard: (Penny looks at Leonard) I got a few rounds left in me.
Penny: Attaboy, champ.

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: 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: 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: I mean, it's not that I think we're living in sin, but I do like the idea that our next act of intimacy will be a legal requirement.

Amy: Maybe we should just get married at City Hall and forget about everything else.
Sheldon: City Hall, hmm. I do like metal detectors and the sound of permits being denied.

Sheldon: Neither of them will be the actual cake. I'm just using it as a bargaining chip to get Amy to agree to the whole wedding party getting rings and us getting one ring to rule them all.
Howard: I forget, which mental hospital are you guys registered at?