I don't know how, but she is cheating! Nobody can be that attractive and this skilled at a videogame

Sheldon

Can we please make a decision? Not only there are children starving in India, there's an Indian starving right here!

Koothrappali [on waiting for food]

Penny: Why can't all guys be like you?
Leonard: Because if all guys were like me the human race couldn't survive

Check out the sexy nurse. I believe it's time for me to turn my head and cough

Wolowitz

Leonard: I understand your impulse to try to physically intimidate me. I mean, you can't compete with me on an intellectual level and so you're driven to animalistic puppery.
Kurt: Call me a "puppy animal?"

Leonard: So, what happens now?
Leslie: Well, I don't know about your sex drive, but I'm probably good till New Year's.
Leonard: Oh. Okay. Thank you.
Leslie: Thank you.
Leonard: You want to make plans for New Year's?
Leslie: Whoa, Leonard, please. You're smothering me

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

Sheldon: Who told you you could touch my board?
Leslie: No one.
Sheldon: I don't come in to 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.
Sheldon: Inconsiderate, that is the adjective, inconsiderate!

Leslie: I'm glad I ran into you. The Physics Department string quartet needs a new cellist.
Leonard: What happened to Elliot Wong?
Leslie: He switched over to high-energy radiation research and had a little mishap, and now the other guys are a little uncomfortable sitting next to him

Leslie: Listen, 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: Well, who wouldn't?
Leslie: Well, the only difference between us and the rat is that you can't stick an electrode in our hypothalamus. That's where you come in

I saw your pupils dilate when you looked at her, which, unless you're a heroin addict, points to sexual attraction

Leslie [about Leonard's interest in Penny]

Leslie: Just so we're clear, you understand that me hanging back to practice 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

TBBT Quotes

Oh, Bernadette, please play my clarinet.

Raj's poem

Sheldon: I'll have a diet Coke.
Penny: Can you please order a cocktail? I need to practice mixing drinks.
Sheldon: Fine... I'll have a virgin Cuba Libre.
Penny: That's... rum and Coke without the rum.
Sheldon: Yes, and would you make it diet?