Raj: To quote Shakespeare, "It is better to have loved and lost than to stay home every night and download increasingly shameful pornography."
Penny: Oh, you poor baby!
Raj: What's wrong with me, Penny?
Penny: Nothing! Nothing. You know, if we weren't friends - and you hadn't brought up that creepy pornography story - I'd be on you like the speed of light squared on matter to make energy.

Raj: Well, to paraphrase Shakespeare: It's better to have loved and lost than to stay home every night and download increasingly shameful pornography.
Penny: Oh... you poor baby.
Raj: What's wrong with me, Penny?
Penny: Nothing, nothing. You know, if we weren't friends - and you hadn't brought up that creepy pornography story - I'd be on you like the speed of light squared on matter to make energy.
Raj: Hey, you totally got that right. E = MC squared.
Penny: I listen. I have no idea what it means, but I listen.

Penny: Oh, okay, look. THIS. NEVER. HAPPENED. Do you understand me?
Raj: (nodding)
Penny: Really?! Still can't talk to me?!

Leonard: What are you doing here?
Raj: I was sleeping!
Leonard: In MY bed?
Raj: Well, I would have slept in my OWN bed, but it was being used to bring shame to my family....and the memory of Gene Roddenberry!

Amy: Have you considered massage?
Sheldon: I'd like to respond to that sarcastically: Yes, I relish the thought of a stranger covering my body with oil and rubbing it.
Amy: I was proposing you massage your muscles with your OWN hands.
Sheldon: (aback) Still sounds like a lot of unnecessary touching...

Bernadette: I was head-hunted by a big pharmaceutical company. They're going to pay me a buttload of money!!
Leonard: Bernadette, that's great!! Howard, do YOU make a buttload?
Howard: Better than what YOU got a buttload of!

Sheldon: Here's an interesting fact about alcohol ... Man is not the only species that ferments fruit in order to become intoxicated. Can you guess what the other is? Hint: sometimes they pack the alcohol in their trunks.
Penny: Monkeys
Sheldon: When does a monkey have a trunk?
Penny: When a suitcase just won't do
Much later - Sheldon: And the answer was elephant.

....I volunteered for the premature ejaculation project. I mean, it's not like either one of us has heart disease.

Bernadette to Howard

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny, get your own Wi-Fi." No spaces.

Raj: Can I bring girls here?
Leonard: You? Sure. Bring as many as you want.
Raj: Okay, deal.
Leonard: Just not against their will.

Come on, dude, I'm exhausted and Tyra Banks says the most important item in your makeup bag is a good night's sleep.

Raj

Amy: Although it is ... microbiology.
Sheldon: Your doctorate is in neurobiology. I fail to see the distinction.
Amy: I'll make it simple for you. I study the brain, the organ responsible for Beethoven's Fifth Symphony. Bernadette studies yeast, the organism responsible for Michelob Lite.

The Big Bang Theory Season 4 Quotes

You have broad hips and a certain corn-fed vigor. Is your womb available for rental?

Sheldon

At best, it's a modest leap forward from the technology that gave us Country Bear Jamboree.

Sheldon