Leonard: We're going to Switzerland to see the CERN supercollider. And ski. We'll also go skiing.
Penny: We're going skiing in Switzerland?
Leonard: Well, you'll ski, I'll fall. But yeah, we will be in Switzerland for Valentine's Day.

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.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Leonard: What would you guys do if you were me?
Wolowitz: I would take Sheldon to Switzerland.
Leonard: Seriously?
Wolowitz: Absolutely. And I'd leave him there.

Sheldon: It was you. I touched you!
Penny: Happy Valentine's Day.

Penny: I think I caught the flu. *Throwing up*. Or the plague!