Penny: Well, I'd ask you guys if you want dessert, but I know Sheldon doesn't eat dessert on Tuesdays. And even if Raj wanted something, he couldn't tell me. Howard won't order anything, but he will come up with some sort of skeevy comment involving the words pie or cheesecake. And Leonard's lactose intolerant, so he can't eat anything here without his intestines blowing up like a balloon animal.
Leonard: Hang on a second. I could have the fruit platter.
Penny: You want the fruit platter?
Leonard: Does it have melon on it?
Penny: Yeah.
Leonard: No, I can't eat melon.

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?

Leonard: Sometimes your movements are so lifelike I forget you are not a real boy.

Raj: Oh, you're so arrogant. If you were a super hero your name would be Captain Arrogant. And do you know what your super power would be? Arrogance.

Sheldon: Oh, Penny. Penny.
Penny: What's up?
Sheldon: Nothing. I just wanted to make Raj stop talking.