Howard: Try telling him it's a non-optional social convention.
Penny: What?
Howard: Just do it!
Penny: It's a non-optional social convention.
Sheldon: Oh, fair enough.
Howard: He came with a manual.

Sheldon: What computer do you have? And please don't say a white one.

Store Clerk: Excuse me, Sir, you don't work here.
Sheldon: Yes, well apparently neither does anyone else.

Howard: Okay, I get it. I know how the world works. How about if I were to introduce you to the man who freed your people.
Nurse: Unless my people were freed by Benjamin Franklin and his five twin brothers, you are wasting your time.

Penny: You keep him there a little longer, and when you get to the party, I'll point out which of my friends are easy.
Howard: Don't toy with me, woman.
Penny: I got a hot former fat girl with no self-esteem. I got a girl who punishes her father by sleeping around, and an alcoholic who's 2 tequila shots away from letting you wear her like a hat.
Howard: Thy will be done.

Sheldon: Penny, if I'm going to get Leonard a gift, I'm going to do it right. I refuse to let him experience the same childhood trauma I did.
Penny: I know I'm gonna regret this, but what trauma?
Sheldon: On my 12th birthday, I really wanted a titanium centrifuge so, you know, I could separate radioactive isotopes.
Penny: Of course, yeah.
Sheldon: Instead of a titanium centrifuge, my parents bought me-- Wow, this is hard. They got me a motorized dirt bike.
Penny: No!
Sheldon: What 12-year-old boy wants a motorized dirt bike?
Penny: All of them.

Penny: That's the saddest thing I've ever heard.
Howard: (to Leonard) Go ahead. Tell her about your senior prom.

Penny: Ok, here's the deal. You either help me throw Leonard a birthday party or, so help me God, I will go into your bedroom and I will unbag all of your most valuable mint condition comic books. And on one of them, you won't know which, I'll draw a tiny happy face.
Sheldon: You can't do that. If you make a mark on a mint comic book, it's no longer mint.
Penny: Sheldon, do you understand the concept of blackmail?

Sheldon: 1234 is not a secure password.

Sheldon: Hello, Penny! Leonard just left.
Penny: I know. I wanna talk to you.
Sheldon: What would we talk about? We have no overlapping areas of interest, as I'm aware of. And you know I don't care for chit-chat.
Penny: Can you just let me in?
Sheldon: Well, OK but I don't see this as a promising endeavor.

Leonard: Howard, every Thai restaurant in town knows you can't eat peanuts. When they see me coming they say, "Ah! No peanut boy!"

Howard: Excuse me.
Althea: Fill this out, have a seat.
Howard: No, listen. See, we're throwing my friend a surprise party and I'm supposed to keep him out of his apartment for two hours.
Althea: Uh-huh. Fill this out and have a seat.
Howard: No, the only way I could get him to leave is to tell him I ate a peanut. Because I'm allergic to peanuts.
Althea: Oh, well in that case fill this out and have a seat.
Howard: Look, all I need from you is to take me in the back and give me a band-aid so I can pretend I had a shot of epinephrine and then you tell my friend you need to keep me under observation for about an hour, hour and a half.
Althea: Is that all you need?
Howard: Yes.
Althea: Get out of my ER.
Howard: No, you don't understand.
Althea: Oh, I understand, but unfortunately this hospital is not equipped to treat stupid.

Leonard: My parents focused on celebrating achievements and being expelled from a birth canal was not considered one of them.

Howard: Okay, I get it, I know how the world works. How about if I were to introduce you to the man who freed your people? (laying down a $5 bill)
Althea: Unless my people were freed by Benjamin Franklin and his 5 twin brothers, you are wasting your time.

Penny: Hey, guys, some of the other waitresses wanted me to ask you something.
Leonard: It's called trestling.
Howard: It combines the physical strength of arm wrestling with the mental agility of tetris into the ultimate sport.
Penny: Yeah, that's terrific, but what they wanted me to ask you was to cut it the hell out.