Leonard: Top of her class, Cambridge University. Licensed to practice law in three countries. And your face.

Penny: What about Howard and Raj? How did he become friends with them?
Leonard: I dunno. How do carbon atoms form a benzene ring? Proximity and valence electrons.
Penny: Sure, when you put it like that.

Penny: God, what is wrong with me.
Leonard: Nothing, you're perfect.
Penny: Gah, I'm not perfect.
Leonard: Yes you are.
Penny: You really think so, don't you? [kisses Leonard]
Leonard: Penny?
Penny: Yeah.
Leonard: How much have you had to drink tonight?
Penny: Just…. a lot.
Leonard: Are you sure that your being drunk, and your being angry with Kurt doesn't have something to do with what's going on here?
Penny: It might. Boy, you're really smart.
Leonard: Yeah, I'm a frickin' genius.

Leonard:What am I supposed to say? Sure, Penny, I'm cool with having your old boyfriend sleep in your apartment.
Leonard imitating Penny: Well, Leonard, it doesn't matter if you're cool or not, 'cause I'm penny and I'm pretty and I can do whatever the hell I want.

Leonard: If he were any bigger, he'd have moons orbiting him.
Sheldon: Oh, snap.

Penny: Leonard, look. Sheldon's hugging me!
Leonard: It's a Saturnalia miracle.

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.

Leonard: You convinced me. Maybe tonight we should sneak in and shampoo her carpet?
Sheldon: You don't think that crosses a line?
Leonard: Yes! For God's sake, Sheldon, do I have to hold up a sarcasm sign every time I open my mouth?
Sheldon: You have a sarcasm sign?

Leonard: What am I supposed to ask her? "Hey Penny, you got any friends that you never want to talk to again?"

Sheldon: Where are my pants?
Leonard: You might wanna check out YouTube.

Leonard: I'm going to the movies with Penny. I don't want her to think I think it's a date.
Sheldon: Do you think it's a date?
Leonard: No, but she might think I think it's a date even though I don't.
Sheldon: Or you might think she thinks you think it's a date even though she doesn't.
Leonard: Are we over thinking this?
Sheldon: Not at all.

Leonard: When he wasn't happy, we wanted to kill him. There was even a plan. We were going to throw his Kindle outside, and when he went to get it, lock the door and let him freeze to death.
Sheldon: That seems like a bit of an overreaction.
Leonard: No, the overreaction was the plan to tie your limbs to four different sled-dog team and yell "Mush!"

Leonard: It's kinda like the Loch Ness Monster. Maybe there's something there, maybe there isn't. We'll never know but sometimes it's fun to creep yourself out thinking about it.

Leonard: I missed you.
Penny: You see me all the time. You sure you don't just miss the sex?
Leonard: Well, yeah, the sex with you is pretty great. Have you ever tried it?
Penny: I have. You're not wrong.

Leonard: I'm going to pick you up at 8. I'm going to show you a night that you will never forget.
Raj: (Excitedly) Where are we going?