They gave him an assistant? If I want a new pen I have to go to the bank with wire cutters

Wolowitz [about Raj]

Raj: Did you see my limo downstairs?
Leonard: Yeah.
Raj: It's bigger than the house my grandfather grew up in.
Leonard: Great.
Raj: It has more food, too

Leonard: It wouldn't kill us to meet new people.
Sheldon: For the record, it could kill us to meet new people

Wolowitz: So you're just going to sit around here and mope while Penny is out with Dr. Apu from the Kwik-E-Mart?
Leonard: It's not a date, and that's racist.
Wolowitz: It can't be racist, he's a beloved character on The Simpsons

Leonard: If we do get a new friend, he should be a guy you can trust. You know, a guy who has your back.
Wolowitz: And he should have a lot of money and live in a cool place down by the beach where we could throw parties.
Sheldon: And he should share our love of technology.
Wolowitz: And he should know a lot of women.
Leonard: Okay, let's see: money, women, technology. Okay, we're agreed. Our new friend is going to be Iron Man

Boy, you'd think you could trust a horde of Hungarian barbarians

Penny

Penny: What's AFK?
Sheldon: Away From Keyboard.
Penny: Oh, I see.
Sheldon: What does that stand for?

Dr. Gablehauser: Dr. Winkle, what colorful name did you call Dr. Cooper this time?
Leslie: Doctor Dumb-ass.

Penny: Oh, my God, a treasure chest. I'm rich!
Sheldon: Level 3 and she thinks she's rich, what a noob.

Raj [to Leonard]: What about Leslie Winkle?
Sheldon: Oh, no.
Raj: Why?
Sheldon: Her research methodology is sloppy, she's unjustifiably arrogant about loop quantum gravity, and to make matters worse, she's often mean to me

Everybody has a date. Even you Mario, going after Princess Peach. What am I doing? I'm just enabling you.

Sheldon

Sheldon: Why should I leave? This is my apartment, too.
Leonard: I know it is. And if science ever discovers a second member of your species, and you two would like some privacy, I'll be more than happy to get out of your way

TBBT Quotes

Mrs. Cooper: Shelly! I'm so glad you're here!
Sheldon: I saw you having naked sex.

Penny: I give up, he's impossible
Sheldon: I can't be impossible, I exist. I believe what you meant to say is, "I give up, he's improbable."