Penny: You don't always have to go along with what the woman wants.
Leonard: Nothing... just re-thinking my whole life
Sheldon: I need to know exactly what Leonard did to get you to put an emotional cap in his buttocks.
Sheldon: Again, urban slang, in which I'm beginning to get remarkable fluency
Penny: Sheldon, what do you want?
Sheldon: I'm certain this will come as no surprise to you, but Leonard is failing in yet another relationship.
Penny: He's having problems with Stephanie?
Sheldon: She's sending virtual livestock to random men on the Internet
Penny: I am going to introduce your friend to a world of hurt.
Leonard: You don't want to get into it with Sheldon. The guy is one lab accident away from being a super villain
Penny: Wait, Sheldon. This has gotten way out of hand. Okay, I've done some stupid things; you've done some stupid things. How about we just call it even and move on with our lives?
Sheldon: I've done no stupid things.
Penny: Look, you've got to meet me half way here.
Sheldon: I am meeting you half-way. I'm willing to concede that you've done some stupid things
Leonard: Just apologize to him, okay?
Penny: What? I'm not going to apologize to that nut-case.
Leonard: Come on, it's easy. He'll even tell you what to say
Wolowitz: Over the years, we've formulated a number of theories about how he might reproduce. I'm an advocate of mitosis.
Penny: I'm sorry?
Wolowitz: I believe one day Sheldon will eat an enormous amount of Thai food and split into two Sheldons.
Leonard: On the other hand, I think Sheldon might be the larval form of his species and someday he'll spin a cocoon and emerge two months later with moth wings and an exoskeleton
Penny [after witnessing Sheldon and Ramona together]: You probably don't want to go in there.
Leonard: Why? What are they doing?
Penny: The only way I could explain it would be in a therapist's office with dolls
Sheldon: Please, please, I don't have a lot of time. Ramona finally dozed off and I need you to help me get rid of her.
Penny: Get rid of her how?
Sheldon: I don't know, but apparently I'm in some kind of relationship, and you seem to be an expert at ending them.
Penny: Excuse me?
Sheldon: I see man after man leaving this apartment, never to return.
Boy, you'd think you could trust a horde of Hungarian barbarians
Penny: What's AFK?
Sheldon: Away From Keyboard.
Penny: Oh, I see.
Sheldon: What does that stand for?
Penny: Oh, my God, a treasure chest. I'm rich!
Sheldon: Level 3 and she thinks she's rich, what a noob.