Amy: So, it's strange, Sheldon was talking in his sleep last night, and he seemed like a totally different person. He was relaxed and loose and calm.
Leonard: Well, Sheldon's a complicated man.
Amy: He said "whatev."
Leonard: Give him a brain scan, that might be a tumor.

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.

Bernadette: One of the great things about being pregnant is drinking cranberry juice out of a wineglass and watching people freak out.

Penny: Is it possible that you're stressed because you're scared about getting married? I mean, it is a big change, and you're not good with little changes.
Sheldon: Well, that's nonsense. You name one little change I was upset with.
Penny: Uh, when they changed the green Skittle from lime to apple.
Sheldon: That is not the rainbow I grew up tasting.

Howard: It's a date. Just pick one.
Sheldon: It's not just a date, it's a textbook optimization problem. There is a perfect date. Just like there's a perfect room temperature and a perfect dessert.
Penny: Mm. There's no perfect dessert.
Sheldon: Yellow cake in the shape of a dinosaur with chocolate frosting, a scoop of vanilla ice cream on the side, not touching. You'll see. You'll have it at our wedding.
Amy: You wanna bet?