Raj: The only thing missing from that insult was "yo momma."
Howard: I've got one. Hey, Leonard, your momma's research methodology is so flawed-
Leonard: Shut up, Howard.

Penny: So, you know, isn't there maybe some way you and Sheldon could compromise on this whole presentation thing.
Leonard: No. No. Scientists do not compromise. Our minds are trained to synthesize facts and come to inarguable conclusions. Not to mention, Sheldon is batcrap crazy.

Howard: Wait a minute, Farminfarmian is speaking and you're bogarting the symposium?
Leonard: Howard, I'm sorry. We're-
Howard: No, no. You're quark-blocking us.

Leonard: I couldn't say that. I would have to say, "You were terrific and I can't wait to hear you sing again."
Sheldon: Why?
Leonard: It's the social protocol. It's what you do when you have a friend who's proud of something they really suck at.
Sheldon: I was not aware of that.
Leonard: Well now you are.

Howard: No, it's okay, it's your Millenium Falcon. You and Chewbacca do whatever you want to do. Me and Princess Leia here will find some other way to spend the evening.

Leonard: Who are you?
Toby: I am Sheldon's cousin Leo.
Leonard: Oh, God! Sheldon does not have a cousin Leo.
Toby: Au contraire. I'm 26 years old. I'm originally from (reads off character profile) Denton, Texas, but I was a Navy brat so I was brought up on a variety of military bases around the world. As a result, I've often felt like an outsider, never really fitting in, which is probably the reason for my substance abuse problem.
Sheldon: Excuse me, we just went over this. As the quintessential middle child, your addiction is rooted in your unmet need for attention.
Toby: Oh, Sheldon, are we really going to go with pop psychology.

Sheldon: I'm sorry, Leonard. This is Toby Loobenfeld. He's a research assistant in the particle physics lab, but he also minored in theater at MIT.
Toby: It was more of a double major actually. Theater and physics. You can guess which one my bourgeois parents pushed me towards.
Leonard: Yeah, I got it.

Sheldon: Is that a dog?
Leonard: Yes.
Sheldon: In the lab?
Leonard: Yes. They're training dogs to operate the centrifuge for when they need dogs to operate the centrifuge for blind scientists, I have to go.

Howard: There's a Planet of the Apes marathon at the New Art today.
Leonard: Five movies, two hours apiece. It's a start.

Penny: Sheldon, what do you want?
Sheldon: I want soup.
Penny: Why didn't you just ... Why didn't you just have soup at home?
Sheldon: Penny, I have an IQ of 187. Don't you imagine that if there were a way for me to have had soup at home I would have thought of it?
Penny: You can have soup delivered.
Sheldon: I did not think of that.

Sheldon: Wait. Will you please rub this on my chest.
Penny: Oh, Sheldon, can't you do that yourself?
Sheldon: Vaporub makes my hands smell funny.
Penny: But Sheldon-
Sheldon: Please, please, please, please, please, please, please.
Penny: I can't believe I'm doing this.
Sheldon: No, no, counter-clockwise or my chest hair mats.

Penny: You deliberately stuck me with Sheldon.
Leonard: Well, I had to, you see what he's like.
Sheldon: Penny! Penny, I'm hungry.
Penny: Uh, it's okay, sweetie. Good news, Leonard's home!
Leonard: No!

Sheldon: Can you sing Soft Kitty?
Penny: What?
Sheldon: My mom used to sing it to me when I was sick.
Penny: I'm sorry, honey, I don't know it.
Sheldon: I'll teach you. [sings] "Soft kitty, warm kitty, little ball of fur, happy kitty, sleepy kitty, purr purr purr." Now you.
Penny: [sighs] [sings] Soft kitty, warm kitty…
Sheldon: Little ball of fur. Keep rubbing.
Penny: Little ball of fur.

Dr. Gablehauser: Gentlemen, I'd like you to meet Dennis Kim. Dennis is a highly sought after doctorial candidate and we're hoping to have him do his graduate work here.
Leonard: Graduate work, very impressive.
Dr. Gablehauser: And he's only fifteen years old.
Sheldon: Not bad, I myself started graduate school at fourteen.
Dennis Kim: Well, I lost a year while my family was tunneling out of North Korea.
Leonard: Advantage Kim.

Howard: You know, Sheldon, you don't have so many friends that you can afford to start insulting them.