Raj: No, no, no, no, that rate is much too low for what you'd expect from this collision. Do you understand we're taking about dark matter colliding in outer space?
Sheldon: Yes, of course I understand, and who are you to tell me about outer space?
Raj: Well, I am the astrophysicist! Astro means space!
Sheldon: Astro means star.
Raj: Okay, let me just tell you, if we were having this argument in my native language, I'd be kicking your butt!
Sheldon: English is your native language!

Okay, please don't take this the wrong way, but I'd rather swim butt-naked across the Ganges with a paper cut on my nipple and die a slow agonizing death from a viral infection than work with you

Raj [to Sheldon]

Wolowitz: So, what are we watching? Sex in the City, yikes!
Penny: Hey, I happen to love this movie.
Wolowitz: Fine, let's watch it. Maybe all our periods will synchronize

I'm going to be deported, sent home in disgrace, exposed to the sardonic barbs of my cousin Sanjay, or as you may know him, Dave from AT&T customer service

Raj

I don't want to go back to India! It's hot, and it's loud, and there are so many people! You have no idea -- they're everywhere.

Raj

Sheldon: Yes, since their relationship became carnal, Penny has updated his designated term of endearment, distinguishing him from those she calls "sweetie," usually as an attempt to soften a thinly-veiled insult.
Penny: You're boring people, sweetie.
Sheldon: Although sometimes, she omits the veil entirely.

Wolowitz: Raj, I'm gonna really miss you.
Raj: Will you come visit me?
Wolowitz: 17 hours is a really long flight, how about we meet halfway?
Raj: Halfway is 600 miles off the coast of Japan
Wolowitz: We'll skype

Leonard: I've always been a little confused abut this -- why don't Hindus eat beef?
Raj: We believe cows are gods.
Sheldon: Not technically. In Hinduism cattle are thought to be like gods.
Raj: Do not tell me about my own culture Sheldon! In the mood I'm in I'll take you out, I swear to cow!

Raj: When we tell the story, let's end it differently
Wolowitz: What are you thinking? A big musical number?

Interesting. Sex works even better than chocolate to modify behavior. I wonder if anyone else has stumbled onto that

Sheldon

Sheldon: Leonard, you can't train my girlfriend like a lab rat
Leonard: Actually, it turns out I can
Sheldon: Well you shouldn't

Yes, she's pushy, and yes, he's whipped, but that's not the expression

Wolowitz [to Raj]

The Big Bang Theory Season 3 Quotes

Wolowitz: Sheldon. You remember the first few weeks; we were looking for magnetic monopoles and not finding anything, and you were acting like an obnoxious, giant dictator?
Raj: I thought we were going to be gentle with him.
Wolowitz: That's why I added the "tator"

Wolowitz [after seeing Penny jump Leonard]: Damnit, I should have gone over and said we were back
Raj: Yeah, it was "first come, first serve."