Sheldon: Sheldon Cooper does not get lucky.
Amy: You and me both, brother.

Sheldon: I've got to find a way to stop this thing.
Leonard: Buddy, I don't think you can. Once it's out there, it's out there. This thing is like the science equivalent of a sex tape.
Sheldon: Frankly, I'd prefer a sex tape.
Leonard: You don't know what a sex tape is, do you?
Sheldon: No.

Bernadette: Great news. A raccoon virus just crossed the species barrier and can now infect humans.
Raj: Why is that great news?
Bernadette: In the pharmaceutical business we have a saying: mo' infections, mo' money.

Penny: Just you wait and see. I'm gonna romance your freakin' ass off.
Leonard: That's beautiful. Is that Shakespeare?

Sheldon: They called it the greatest thing since the Communist party. Although I'm pretty sure the Communist party made them say that. I like China. See, they know how to keep people in line.

Sheldon: How do I make them stop loving me?
Leonard: You could invite them to live with us.

Leonard: People get things they don't deserve all the time. Like me with you.

Howard: So I'm almost done writing the song for Bernadette. Are you cool playing the cello?
Leonard: If by cool you mean willing to, yes. If by cool you mean cool, clearly you've never seen me play the cello.

Sheldon: Don't worry. I will remain the same down to earth, humble Joe I've always been.
Leonard: Good to know.
Sheldon: Now give me that cookie, I discovered an element.

Leonard: I get that you feel bad about all the attention, but still what you did is amazing. We're really proud of you.
Amy: I'm not.
Sheldon: You're not?
Amy: Sheldon, I've been thinking about it and you're right. You don't deserve any credit. All you did was misread some numbers on a table. A very easy table, too. Honestly, I'm embarrassed for you.
Sheldon: That's the most romantic thing I've ever heard.
Penny: Damn it, everyone's better at this than me.
Sheldon: Congratulations, Dr. Fowler. You just made the fort.

Penny: Sheldon, you wanna take a break? Your food's ready.
Leonard: What are you doing? He's both happy and quiet. It's like seeing a unicorn and big foot at the same time.

Sheldon: The National Science Foundation wants to give me a substantial grant.
Raj: That's a big deal.
Sheldon: I know. When will this nightmare end?

Penny: Bernadette is going to love this.
Leonard: Yeah, it must be nice to have somebody do something so romantic.
Penny: Okay, you know what's not romantic? Rubbing it in someone's face.
Leonard: Actually, it can be. But I told you sex doesn't count.

Penny: What are you working on?
Sheldon: Can't talk. In the zone.
Penny: (To Amy) Do you know what he's doing?
Amy: Could be anything. Last time he was like this he figured out electron transport in graphene. The time before that he was making a list of who's allowed in his tree fort if he ever gets one. Still can't believe I didn't make the cut.

Penny: How come you've never done anything romantic to celebrate our first date?
Leonard: For starters, you've broken up with me so many times, which first date are we talking about?
Sheldon: Oh, somebody call the burn ward. ... And back to the zone.