Leonard: I'm not sure it's a good idea to take Penny to where wine comes from.

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.

Amy: I don't know what made me think tonight would be any different.
Bernadette: Well just the fact you got him up here says a lot. To be honest, I bet Howie $200 that it wasn't going to happen.
Howard: I'm going to the Lego Store to get a big-ass R2D2.
Bernadette: See, it's not just Sheldon, they're all idiots.
Howard: She's right.

Sheldon: What is your problem?
Amy: It's Valentine's day. We're supposed to be having a romantic weekend.
Sheldon: Oh, really? 'cause I remember you saying this trip was going to be something we could both enjoy. Did you mean that or were you just trying to trick me?
Amy: Fine, it's true. I deserve romance and I didn't know how else to make it happen.

Sheldon: The conductor said if I come back to the engine room, he'd show me how to take the train through a crossing.
Amy: Okay. Have fun.
Sheldon: Do you want to come with me?
Amy: Really? I do!