Sheldon: Who do I speak to about permanently reserving this table?
Penny: I don't know, a psychiatrist?

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.

Sheldon: I don't know what the protocol is here. Do I stay, do I leave? Do I wait to greet them with a refreshing beverage?
Penny: Gee, Sheldon, you're asking the wrong girl. I'm usually on the other side of the tie.

Sheldon: I need your help in a matter of semiotics.
Penny: What?
Sheldon: Semiotics, the study of signs and symbols as a branch of the philosophy related to linguistics.
Penny: Okay, honey, I know you think you are explaining yourself, but you're really not.

Leslie: Listen Leonard, neither of us are neuro-scientists, but we both understand the bio-chemistry of sex, ... I mean: Dopamine in our brain is released across synapses causing pleasure. You stick electrodes in a rat's brain, give him an orgasm button and he'll push that thing 'till he starves to death.
Leonard: Who wouldn't?

Leonard: Leslie, this is Penny, she lives across the hall from Sheldon and me.
Howard: ... And walks in quiet beauty like the night.
Penny: Howard, I asked you not to do that.

Sheldon: My equations, someone's tampered with my equations.
Leonard: Are you sure?
Sheldon: Of course I'm sure. Look at the beta function of quantum chromodynamics. The sign's been changed.
Leonard: Oh, yeah. But doesn't that fix the problem you've been having?
Sheldon: Are you insane? Are you out of your mind? (looking at board) Are you--? Hey, look, that fixes the problem I've been having.

Sheldon: Can't we just go to Big Boy? They only have one burger: the Big Boy.
Penny: The Barbecue Burger is like the Big Boy.
Sheldon: Excuse me, in a world that already includes a Big Boy, why would I settle for something that's like a Big Boy?

Leslie: Come for the breasts, stay for the brains!

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.

Penny: Leonard's had girls over before, right?
Sheldon: Oh, yes, but there's usually planning, courtship and advance notice. Last time I was able to book a cruise to the Arctic to see a solar eclipse.
Penny: Wait, you had to leave the state because your roommate was having sex?
Sheldon: I didn't have to, the dates just happened to coincide.

Sheldon: Waitresses don't yell at you at Big Boy.

Leslie: Oh, Leonard, you magnificent beast.

Leslie: I didn't know you eat here.
Sheldon: We don't, this is a disturbing aberration.

Leslie: Just so we're clear, you understand that me hanging back to practise with you is a pretext for letting you know that I'm sexually available.
Leonard: Really?
Leslie: Yeah, I'm good to go.
Leonard: I thought you weren't interested in me.
Leslie: That was before I saw you handling that beautiful piece of wood between your legs.
Leonard: You mean my cello?
Leslie: No, I mean the obvious crude double entendre. I'm seducing you.

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

Howard: Hang on, honey. Shiva and Ganesh? The Hindu Gods against the entire Union army?
Leonard: And Orcs!
Penny: I'll be back.
Raj: Excuse me, Ganesh is the remover of obstacles, and Shiva is the destroyer. When the smoke clears, Abraham Lincoln will be speaking Hindi and drinking mint juleps.

Leonard: What did Penny mean, you'd make a cute couple?
Sheldon: Well I assume she meant that the two of you together would constitute a couple that others might consider cute. An alternate, and somewhat less likely interpretation, is that you could manufacture one. As in, oh look, Leonard and Leslie made Mr. and Mrs. Goldfarb, aren't they adorable.

Sheldon: Boy, you're wound awfully tight for a man who just had sexual intercourse.

Howard: What do you recommend for someone who worked up a man-sized appetite from a morning of weight training and cardio funk?
Penny: A shower.

Howard: I'll take the heart smart platter.
Penny: Alright, thank you, and Sheldon.
Sheldon: We don't eat here. I don't know what's good.
Penny: Well, it's all good.
Sheldon: Statistically unlikely.

Raj: Oh dear.
Howard: What's the matter?
Raj: She didn't take my order.
Howard: How can she take your order when you're too neurotic to talk to her?
Raj: Nevertheless, this will be reflected in her tip.

Penny: Alright, look, a tie on the doorknob usually means someone doesn't want to be disturbed because they’re, you know, getting busy.
Sheldon: So you're saying Leonard has a girl in there.
Penny: Well, either that or he's lost his tie rack and gotten really into Bryan Adams.

Sheldon: Do you realise I may have to share a Nobel Prize with your booty call?
Leonard: You know what, I'm being ridiculous. Who cares what Penny thinks? Leslie is a terrific girl. She's attractive, we like each other, she's extremely intelligent.
Sheldon: She's not that intelligent.
Leonard: She fixed your equation.
Sheldon: She got lucky.
Leonard: You don't believe in luck.
Sheldon: I don't have to believe in it for her to be lucky.

Leonard: Well what did she mean by that? Was that just a generic platitude or was that a subtle bid for attention?
Sheldon: You know why this hamburger surpasses the Big Boy? This is a single decker hamburger whereas the Big Boy is a double decker. This has a much more satisfying meat to bun to condiment ratio.
Leonard: Are you even listening to me?
Sheldon: Of course I'm listening. Blah blah, hopeless Penny delusion, blah blah blah.

Leslie: Listen, Leonard, neither of us are neuroscientists but we both understand the biochemistry of sex. I mean, dopamine in our brains is released across synapses causing pleasure. You stick electrodes in a rat's brain, give him an orgasm button, he'll push that thing until he starves to death.
Leonard: Who wouldn't?
Leslie: Well, the only difference between us and a rat is that you can't stick an electrode in our hypothalamus. That's where you come in.
Leonard: Yeah, well, I'm just glad to be a part of it. So what happens now?
Leslie: Well, I don't know about your sex drive, but I'm probably good till New Years.

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.

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.

Penny: So, do you know who's in there?
Sheldon: Well, there's Leonard. ... (Picking up violin case) And he's either with Leslie Winkle or a 1930s gangster.

Sheldon: Alright, I'm moving my infantry division, augmented by a battalion of Orcs from Lord of the Rings, we flank the Tennessee Volunteers, and the North once again wins the Battle of Gettysburg.
Howard: Not so fast, remember the South still has two infantry divisions, plus Superman and Godzilla.
Leonard: No, no, no, no, Orcs are magic, Superman is vulnerable to magic, not to mention, you already lost Godzilla to the Illinois Cavalry and Hulk.
Raj: Why don't you just have Robert E. Lee charge the line with Shiva and Ganesh?

Leslie: Is it the waitress?
Leonard: Penny? What about her?
Leslie: Well, I thought I saw your pupils dilate when you looked at her, which, unless you're a heroin addict, points to sexual attraction.

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.