Penny: Ah, it's nice having the place to ourselves, isn't it?
Leonard: Uh-huh. Now that Raj is working for Sheldon, I don't have to chauffeur him around anymore. Plus, yeah, with them working late so much, we get some privacy.
Penny: Mm-hmm. Hey, want to get a little crazy?
Leonard: What are you thinking?
Penny: Let's slide over to Sheldon's spot and make out.
Leonard: You are a dirty girl.

Leonard: Dr. Cooper?
Louis: No, you want the crazy guy next door.

Leonard: Not only did Sheldon save my life, he didn't rat me out to the landlord. Or the police. Or Homeland Security.
Penny: Okay, so, basically, you're the reason I have to walk up and down three flights of stairs every day?

Leonard: There you go, three against one.
Sheldon: They don't get a vote. It's one against one. And according to the roommate agreement, all ties will be settled by me.
Leonard: But I said no to that.
Sheldon: And I said yes. And I settle all ties.

Penny: Why on earth did you agree to all that?
Leonard: It was the best apartment I'd seen, the rent was very reasonable and after you've passed the first three barriers you kind of want to take it all the way.
Penny: Well, I'm sorry, Leonard, it's very hard to feel sympathy for you.

Sheldon: Section nine, miscellany. The apartment's flag is a gold lion rampant on a field of azure.
Leonard: We have a flag?
Sheldon: Never fly it upside down unless the apartment's in distress.

Leonard: Do I get some sympathy now?
Penny: A little bit. Okay. Let me get this straight. You move in with this guy, he makes you sign a ridiculous roommate agreement, then he walks into your bedroom while you're doing this Joyce Kim, and you still stay?
Leonard: Actually, I couldn't get too mad at him about Joyce Kim.
Penny: Why not?
Leonard: Well, I was doing some government research at the time, you know, military, rocket fuel. It's kind of secret.
Penny: What does that have to do with Joyce Kim?
Leonard: As it turns out, she was a North Korean spy. Luckily, Sheldon drove her out before I revealed anything important. Which I'm not saying I would have.

Sheldon: Third barrier passed. You have won the right to see your room. Huzzah!
Leonard: Is this it?
Sheldon: No, this is my room. People don't go in my room.
Leonard: So where do you sleep?
Sheldon: I don't understand.
Leonard: If people don't go in there, and you're people, and… You are people, aren't you? Making a joke.
Sheldon: Do you do this often?
Leonard: On occasion.

Sheldon: Roommates agree that Friday nights shall be reserved for watching Joss Whedon's brilliant new series Firefly.
Leonard: Does that really need to be in the agreement?
Sheldon: We might as well settle it now, it's going to be on for years.

Sheldon: And next, if either of us ever invents time travel, we agree our first stop will be this meeting today in precisely five seconds.
Leonard: Okay. [They look around, nothing happens]
Sheldon: Well that's disappointing.

Sheldon: All right, next question. Kirk or Picard?
Leonard: Oh, uh, well, that's tricky. Um, well, uh, Original Series over Next Generation, but Picard over Kirk.
Sheldon: Correct. You've passed the first barrier to roommate-hood. You may enter.

Sheldon: That's correct. FYI, I would have accepted any answer other than procreating. Come, I'll show you the rest of the apartment.
Leonard: Oh, good. I passed the barriers.
Sheldon: The second barrier. Don't get cocky.

Leonard: Oh, this is pretty nice. Uh, the bedrooms are back there?
Sheldon: That depends.
Leonard: I don't understand, their, their existence is conditional?
Sheldon: No, but your ability to perceive their existence is conditional on you passing the second and third barriers.
Leonard: There's three?
Sheldon: Each more daunting than the last. Have a seat.

Sheldon: (Knock * 3) Leonard?
Leonard: Shh. Just pretend we're not here.
Sheldon: (Knock * 3) Leonard?
Leonard: I'm sure he'll go away.
Sheldon: I'm just going to keep knocking till you answer. (Knock * 3) Leonard? (Knock * 3) Leonard? (Knock * 3) Leonard?
Leonard: What do you want? I didn't say come in!
Sheldon: You asked what I wanted. I wanted to come in. I'm here because you violated our roommate agreement. Specifically, section eight, visitors, subsection C, females, paragraph four, coitus. Roommates shall give each other 12 hours notice of impending coitus.
Leonard: I didn't even know her 12 hours ago.
Joyce Kim: That's it! I'm out of here!
Leonard: But, Joyce, come on.
Sheldon: 12 hours? [Looking judgmentally]

Sheldon: Are you bothered that I can so easily manipulate you?
Howard: Don't push me, Sheldon. I may be small, but I took kung fu when I was 13, and I remember a good deal of it.
Sheldon: Oh, really? Well, I grew up with an older brother and a very contentious twin sister and I believe I could easily best you in any physical confrontation, be it noogies, swirlies or the classic why are you hitting yourself?