Howard: Nice to see that the gals are getting along.
Leonard: Gals? Who are you, Fred Flintstone?

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.

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

Raj: She didn't even get to see my penis.

Sheldon: There's no need to interact with me. I'm just here to observe.

Penny: I'm sorry, shoes, but you have to go back.
Shoebox (Penny): But, Penny, we love you.
Penny: I love you, too, but you cost more than my rent.
Shoebox (Penny): But Penny, you look so good in us.
Penny: (To Amy) Damn it, the shoes are right!