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.

Raj: Leonard, give me a beat.
Leonard: I will not.

Howard: Oh, Bernie. What happened?
Bernadette: Let's just say the next time you move a dozen vials of raccoon virus to the fridge, make two trips.

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.

Sheldon: I hate to pile on the bad news, but I just got a raise.

Penny: What's thoughtful is everything you do. Here, look at this. This is the plane ticket you bought me when I was too poor to go home for the holidays. And the rose you left on my windshield just because. Here's the thank you letter you wrote me after the first time I slept with you. All eleven pages of it.
Leonard: I can't believe you saved all this stuff.
Penny: Of course I did, it's you.
Leonard: Come here. ... Is that a pregnancy test?
Penny: Oh yeah, just the first one. I didn't save them all.

Sheldon: This is the magic marker I was using when I made the discovery.
Amy: I don't think the Smithsonian is gonna want your marker.
Sheldon: And that's why you're not on my list for the tree fort.

Leonard: Besides, can you even name one romantic thing you've done for me?
Penny: I can name tons.
Leonard: And sex doesn't count.
Penny: Oh.

Raj: Penny, if you truly want to be romantic it has to come from you.
Penny: I get that, but why is this so hard?
Raj: You've probably never had to do this before because you're young and beautiful, and men have always thrown themselves at you.
Penny: Yeah, I'm trying to be sad about that. I can't.

Sheldon: Oh stop it. I don't need to take this admiration from the likes of you people.

Raj: Well, I've always had this fantasy that involves dancing. The sexual chemistry between my partner and me. But boy oh boy, does my father not approve until he sees us in the big dance competition.
Penny: Okay, that's just the plot for "Dirty Dancing".

Penny: Aww, what horrible thing are you trying to make up for?
Howard: Just putting something in the bank for what horrible thing I do next.

Penny: I don't know if I wanna cook for him. He's kind of a picky eater. "It's too salty. It's too dry. It's too burnt and frozen at the same time."

Howard: (To Raj) Will you play the ukelele?
Raj: Sure, I'd be happy to shred it on my axe.
Howard: Or you could just play your tiny, ridiculous guitar.

Howard: You sure you're okay?
Bernadette: Yeah, it's just a precaution. If there were a problem I'd be throwing up through my eyeballs by now.

Raj: As I'm sure you're aware the quickest way to a man's heart is through his -
Penny: Pants. But Leonard said sex doesn't count.
Raj: You poor thing. You have one arrow in your quiver and you just can't use it.

Penny: What else would you love? Other than being lifted over Patrick Swayze's head.
Raj: Oh, you could stand outside with a boombox in the air.
Penny: That's from "Say Anything".
Raj: Look, I'm a lonely guy. I watch a lot of movies.

Raj: I don't call anyone a whore, and the only time I use the phrase "my bitch", I'm referring to you (Howard).