Leonard: I wish you could stay in LA a while longer.
Priya: Mmm. Me too.
Leonard: You know, I was thinking, there are some great research facilities in India.
Priya: Where are you going with this, Leonard?
Leonard: Well, I'm just saying, I don't have any real ties here, so if I were to move to New Delhi we could, you know, go out.
Priya: Leonard, didn't we have this conversation five years ago.
Leonard: Well, yes, but, things have changed. You know, you're older, I'm older. Look, no more superhero bedsheets.

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: I'm sorry.
Raj's sister: Why do you say that?
Leonard: When I'm in bed with a girl, that's just my natural response.

Raj: Hands off my sister.
Sheldon: Why would I touch your sister? She's all covered in airplane germs.

Sheldon: And to think, I was about to waste the last of my good haemorrhoid cream on you.