Penny: This is so sweet. You never cook for me.
Leonard: Well, you cook for me all the time and eugh.
Penny: If you don't like my cooking, why haven't you ever said anything?
Leonard: Well, it's hard to talk with so much heavy chewing to do.

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.

Penny: [on the phone] No, mom. It's the same guy I've been going out with for the past two years. Yeah, the scientist. Well, it's complicated. He works with lasers and atomic magnets. No, I did not see it coming. No, we have not set a date. No, I am not pregnant. Yeah, this is a first for our family.

Howard: Hang on, I know a place where you could you stay and earn some money at the same time.
Stuart: Great!
Howard: I just have to warn you: it will involve humiliation, degradation and verbal abuse.
Stuart: So, what's the catch?

Bernadette: But we have jobs, we can't babysit her twenty-four hours a day.
Howard: What if we use our vacation time?
Bernadette: I wanted to go to Hawaii, not Hell.