Leonard: Are you sure?
Penny: Well, have you slept with her yet? ... You dog! Good for you.
Leonard: Does that change things?
Penny: No.
Leonard: So why'd you ask?
Penny: I'm nosy. See ya.

Leonard: Hi, Howard. Howard?
Howard: Sheldon.
Sheldon: Howard is employing a schoolyard paradigm in which you are, for all intents and purposes, deceased. He intends to act on this by not speaking to you, feigning an inability to hear you when you speak and otherwise refusing to acknowledge your existence.
Leonard: That's just ridiculous. Why are you cooperating with him?
Sheldon: I don't make the rules, Leonard.

Leonard: Howard, come on, I didn't plan on this. These things just happen. Usually not to me, but they do happen.
Howard: Did someone just feel a cold breeze?
Sheldon: I believe this is an extension of the death metaphor. The cold breeze is the so-called ectoplasmic issue of a disembodied soul passing by.

Raj: Hold on a second. Kreplach??
Howard: Yeah.
Raj: That isn't Klingon. It's yiddish for meat-filled dumpling!
Howard: Well, as it turns out it's also a Klingon word.
Leonard: Really? Define it.
Howard: Kreplach a hearty Klingon.....dumpling.

Sheldon: Is my hamburger medium-well?
Leonard: Yes.
Sheldon: Dill slices not sweet?
Leonard: Yes.
Sheldon: Individual relish packets?
Leonard: Yes.
Sheldon: Onion rings?
Leonard: Yes.
Sheldon: Extra-breading?
Leonard: I asked.
Sheldon: What did they say?
Leonard: No.
Sheldon: Did you protest?
Leonard: Yes.
Sheldon: Vociferously?
Leonard: No.
Sheldon: Well then what took you so long?

Wolowitz (watching America's Next Top Model): Oh, look! That's the future Mrs. Wolowitz. No, wait! That's the future Mrs. Wolowitz. With her head in the lap of... what a coincidence... it's the future Mrs. Wolowitz.
Leonard: Yeah, and they can all move in with you and your mother. The current Mrs. Wolowitz.

Wolowitz: If it's "creepy" to use the Internet, military satellites, and robot aircraft to find a house full of gorgeous young models so I can drop in on them unexpected, then fine, I'm "creepy".

Penny: Oh, I didn’t tell you? You’re banished from the Cheesecake Factory.
Sheldon: Why?
Penny: Well, you have three strikes. One, coming in. Two, sitting down. And three, I don’t like your attitude.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Sheldon: *On computer screen* Greetings, hamburger toucher. You are probably wondering why you cannot IM with your little friends about how much you heart various things. Well, this recorded message is alerting you that I am putting an end to your parasitic piggybacking upon our WiFi. If you want to remedy the situation you can contact the phone company, set up your own WiFi and pay for it, or you may apologize to me.

Leonard: Penny, you don't want to get into it with Sheldon. The guy's one lab accident away from being a super villain.

Sheldon: And then you put it back, compromising the rest of the onion rings.
Penny: Aw honey, the buses don't go where you live do they?

Sheldon: When you understand the laws of physics, Penny, anything is possible. And may I add, "Mwah, ha, ha."

Penny: No Shoes, No Shirt, No Sheldon.
Howard: I bet we could sell that sign all over Pasadena!

Sheldon: Excuse me, Penny, but-
Leonard: Don't tell her.
Sheldon: We're playing Klingon Boggle.
Leonard: Aww!
Howard: What do you mean "Aww?" Like she didn't know we were nerds?