Dave: I don't know how you live next door to that without doing something about it.
Leonard: Actually, science is my lady.

Leonard: I've been offering to show you around for a year and a half. You always said you had yoga.
Penny: I never said that.
Leonard: Maybe I heard you wrong. A lot of words sound like yoga.

Leonard: Oh, then I think you'll appreciate what I got you.
Penny: Okay. 101 Totally Cool Science Experiments for Kids.
Leonard: You know, 'cause you're so into science.

Stephanie: I don't see anything at all, Sheldon.
Sheldon: Well, you're the doctor, but I am constantly hearing this annoying sound.
Leonard: Me too.
Sheldon: Is it a high frequency whistle?
Leonard: No, it's more of a relentless, narcissistic drone.

Leonard: No, absolutely not.
Sheldon: It's not a big deal.We have latex gloves.
Leonard: I don't care what the symptoms are. My girlfriend is not going to give you a prostate exam.

Sheldon: I've never once been invited to have cereal with Mrs. Vartabedian.
Leonard: She doesn't like you.

Leonard: Where's my Bat Signal?
Penny: You have a Bat Signal?
Leonard: I did. It was right here. She must have- Oh, my God, we're living together.

Howard: New pants?
Leonard: Yeah, Stephanie got them for me.
Howard: Nice. Cotton?
Leonard: Actually, I think it's more of a wool-fire ant blend.

Stephanie: I just performed a Sheldonectomy.
Leonard: Careful, if you don't get it all, it'll only come back worse.

Leonard: Look, I'm just saying, um, Penny is one of our many neighbors, you know, and in our building, neighbors come and go, it's very casual, no dress code. In fact, some mornings I'll just mosey down to the third floor in my pajamas and have cereal with Mrs. Vartabedian.
Sheldon: Really? I have never once been invited to have cereal with Mrs. Vartabedian.
Leonard: She doesn't like you.

Leonard: I don't care what you guys think, Stephanie and I are very happy living together. I will give either of you 20 dollars, right now to trade pants with me!

Howard: You know, if you can't talk to her, why don't you just text her?
Leonard: Isn't that kind of cowardly?
Howard: Oh, yeah. It's beyond contemptible.
Raj: It's true, but on the other hand you are wearing a bird sweater.
Leonard: Sold.

Sheldon: *knock knock knock* Leonard? (x3)
Leonard: What, Sheldon!? What, Sheldon!? What, Sheldon!?
Sheldon: Tell me what you see here.
Leonard: The blunt instrument that will be the focus of my murder trial?

Sheldon: Hi, Stephanie. I'm sorry I'm late, but your companion left the most indecipherable invitation.
Leonard: What invitation?
Sheldon: "We're going to the movies." What movie? What theater? What time? If you were trying to make it impossible to locate you, you couldn't have done a better job.
Leonard: Oh, clearly I could have.
Sheldon: It took me nearly 20 minutes to go through the browser history on your computer to see what movie times you looked up.

Stephanie: So, how was your day?
Leonard: You know, I'm a physicist, I thought about stuff.
Stephanie: That's it?
Leonard: I wrote some of it down.