Leonard [watching their fight on YouTube]: Oh, geez, does this suit really look that bad?
Sheldon: Forget your suit. Look at my arms flailing. I'm like a flamingo on Ritalin

Leonard: Sheldon, why is this letter in the trash?
Sheldon: Well, there's always the possibility that a trash can spontaneously formed around the letter, but Occam's Razor would suggest that someone threw it out

Leonard: You are not Isaac Newton.
Sheldon: No, no, that's true. Gravity would have been apparent to me without the apple

Sheldon: I shower twice a day and wash my hands as often as I can.
Lalita: Really? So do I!
Raj: But you're a dentist, he's nuts

Sheldon: You are the living embodiment of the beautiful Princess Panchali.
Lalita: Oh, no kidding? Who is that?
Sheldon: A beloved character from an Indian folktale.
Lalita: Oh. "Us" Indian or "Come to our casino" Indian?
Sheldon: "You" Indian

Leonard [referring to Sheldon singing]: What got into him?
Penny: Oh, just a couple virgin Cuba Libres that turned out to be kinda slutty

How can I be a gynocologist? I can barely look a woman in the eye!

Raj

I had such plans. I had dreams. I was going to be the Indira Gandhi of particle astrophysics... but with a penis, of course

Raj

Leonard: Look at the bright side. [Lalita] might turn out to be a nice, beautiful girl.
Raj: Great, then we'll get married, I won't be able to talk to her, and we'll spend the rest of our lives in total silence.
Wolowitz: Worked for my parents

Is it just me, or does webchatting with your clothes on seem a little pointless?

Wolowitz

Penny [to Raj about Lalita]: No one can make you get married. Why don't you just meet this girl and see what happens?
Raj: Haven't you been listening to me? I cannot talk to women!
Leonard: Um, Raj?
Wolowitz: No, no, let's see how long it takes him

Sheldon: When I was a little boy and got sick, which was most of the time, my mother would read [The Monkey and the Princess] to me. It's about an Indian princess who befriends a monkey who was mocked by all the other monkeys because he was different. For some reason I related to it quite strongly.
Penny: I know the reason.
Leonard: We all know the reason

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?