Raj: You know what? Even though I don't have a girlfriend, I can still have a good time on Valentine's Day.
Howard: Trust me, you can't. I've tried.
Raj: No, no, no, I’m going to have a me day. First I’m going to go to one of those spas in Koreatown, take a steam and get a massage. Then I’m going to stop at a pet store and get licked by puppies.

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Bernadette: Maybe we should get one of those machines to help her up the stairs.
Howard: You mean a forklift?

Sheldon: Sheldon Cooper does not cry.
Howard: That's true, you'd rust.

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.

Sheldon: Hello.
Penny: Hello.
Sheldon: Ok, enough with the friendly banter. I believe you know why I am here.
Penny: Oh, I always figured it was to study us, discover our weaknesses, and report back to your alien overlords.
Sheldon: Yes amusing. Extraordinary intelligence might well appear extraterrestrial to you, but let me be more specific. I believe you know why I am here in the laundry room.