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: I call Frodo!
Sheldon, Raj, and Howard: Damn!

Leonard: There's not going to be a confrontation. I bet he can't even spell confrontation.
Kurt: C-O-N...frontation.

Leonard: If Penny didn't know that Leslie had already turned me down then that would unambiguously mean that she, Penny, thought I should ask her, Leslie, out, indicating that she, Penny, had no interest in me asking her, Penny, out but because she did know that I had asked Leslie out and that she, Leslie, had turned me down then she, Penny, could be offering me consolation. "That's too bad, you would have made a cute couple" but while thinking "good, Leonard remains available."
Sheldon: You're a lucky man Leonard.
Leonard: How so?
Sheldon: You're talking to one of three men in the western hemisphere capable of following that train of thought.
Leonard: Well, what do you think?
Sheldon: I said I could follow it, I didn't say I cared.

Penny: Leonard, I didn't know you played the cello?
Leonard: Yeah, my parents felt that naming me Leonard and putting me in advanced placement classes wasn't getting me beaten up enough.

Leslie: I admire your fingering.
Leonard: Thank you.
Leslie: Maybe some time you can try that on my instrument.

Sheldon: I don't come into your house and touch your board.
Leslie: There are no incorrect equations on my board.
Sheldon: Oh, that is so... so...
Leslie: I'm sorry, I've got to run. If you come up with an adjective, text me.

Leonard: Thank you. What did she mean, "she's happy for me"? Is she happy because I'm seeing someone or is she happy because she thinks that I'm happy? Because anyone who cared for someone would want them to be happy, even if the reason for their happiness made the first person unhappy. You know, because the second person, though happy, is now romantically unavailable to the first person.

Leslie: Uh, what are you doing?
Leonard: Just extending the intimacy. Do you want to slip over to the radiation lab and share a decontamination shower?
Leslie: Okay, uh, what exactly do you think's going on between us?
Leonard: I'm not sure, but I think I'm about to discover how the banana felt.

Mary Cooper: You know, you two make a cute couple.
Leonard: No, no we're not, we're not a couple, we're single, two singles, like those individually wrapped slices of cheese that are friends.
Mary Cooper: Did I pluck a nerve there?
Howard: Oh yeah.

Wolowitz: So, how'd it go with Leslie?
Leonard: Oh, we tried kissing, but the earth didn't move. I mean any more than the 383 miles it was gonna move anyway.

Sheldon: Whoo! I'm all sweaty. Anybody wanna log on to Second Life and go swimming? I just built a virtual pool.
Leonard: No, I can't look at you or your avatar right now.

Doug: What's up, bro?
Leonard: Uh, nothing much... Bro!

Leonard: I was thinking more of a biosocial exploration with a neurochemical overlay.
Leslie: Wait, are you asking me out?

Howard: Alright, just a few more feet, and ... here we are gentlemen, the Gates of Elzebob.
Sheldon: Good lord!
Raj: Oooh.
Leonard: Don't panic, this is what the last 97 hours have been about.