Penny: (crying) How could he do that?
Leonard: Oh, you did throw an 80-gig iPod-- Yeah, no, how could he do that?

Leonard: Elevators, parks, movie theaters. Out of curiosity, is this subway, the transportation system, or Subway, the sandwich shop?
Penny: Sandwich shop.
Leonard: Doesn't that violate the health code or--?
Penny: No, at the sandwich shop, we were only making out.

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

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

Leonard: Look, I am in the Halo battle of my life here. There's this kid in Copenhagen. He has no immune system so all he does is sit in his bubble and play Halo 24/7.
Howard: Can't you play him some other time?
Leonard: Not if you believe his doctors.

Leonard: Here you go, Copenhagen boy, how about a taste of Hans Christian Hand Grenade.

Raj: (Reading Bulletin) We are testing a new medication for social anxiety, panic attacks, agoraphobia and obsessive-compulsive disorder. Why would they be looking for test subjects here?
Leonard: I don't know, Raj, maybe the comic store doesn't have a bulletin board.

Howard: You've already got Penny?
Leonard: How do I have Penny? In what universe do I have Penny?
Howard: So I can have Penny?
Leonard: Hell, no!

Leonard: Can I go back and prevent you from explaining that to me?
Sheldon: Same paradox. If you were to travel back in time and, say, knock me unconscious, you would not then have the conversation that irritated you, motivating you to go back and knock me unconscious.
Leonard: What if I knock you unconscious now?
Sheldon: It won't change the past.
Leonard: But it'd make the present so much nicer.

Raj: Did the listing actually saying "Miniature"?
Leonard: (Looking at time machine) I just assumed.

Penny: Damn, okay, Ill just take the roof.
Leonard: Hey, if you wait for us to set up the time machine, I can drop you off at work yesterday. Time travel joke. It's not ... never mind.
Sheldon: For what it's worth, I thought it was humorous.

Sheldon: What are you doing?
Leonard: I'm packing up all my collectibles and taking them down to the comic book store to sell.
Sheldon: Well, is that really necessary? If you need money you can always sell blood. And semen.
Leonard: It's not about money.

Leonard: Okay, Sheldon, I understand that youre going through a bit of a career crisis, you're searching for some other area where you can feel valuable and productive but I need to tell you something and I want you to listen carefully.
Sheldon: All right.
Leonard: Go away!

Leonard: Sure, if he wants to spend years doing her homework while she drinks herself into a stupor with non-fat White Russians and you're the one holding her head while she's puking and telling you she wishes more guys were like you. And then she gets into Cornell, because you wrote her essay for her and you drive up to visit her one weekend and she acts like she doesn't even know you.

Howard: Unbelievable! Components I built are on the International Space Station and I get a ticket for launching a rocket in the park.
Leonard: I don't know if the ticket was so much for the launch as for telling the policewoman "You have to frisk me, I have another rocket in my pants"!