Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Professor Proton: Can I ask you a question?
Leonard: Yeah, sure.
Professor Proton: Why do you put up with Sheldon?
Leonard: Oh, you know because we're friends.
Professor Proton: Why?
Leonard: Wow, you ask really hard questions. Look, I know he can be aggravating, but what you have to remember is he's not doing it on purpose, it's just how he is. But he's also loyal and trustworthy and we have fun together.
Professor Proton: You know you're describing a dog?
Leonard: He did bite me once. But in his defense, I came up behind him while he was eating.
Professor Proton: They hate that.
Leonard: Sheldon is the smartest person I have met. He's a little broken and he needs me. And I guess I need him too.
Professor Proton: Why is that?
Leonard: Boy, you will not let this go, will you?

Amy's Mom: It's nice to meet you too Sheldon, I honestly didn't believe Amy when she told me she had a boyfriend.
Sheldon: I assure you, I am quite real and I'm having regular intercourse with your daughter.
Amy's Mom: What?
Sheldon: Oh yes, We're like wild animals in heat. It's a wonder neither of us has been hurt!
Amy's Mom: Amy? What is he saying?
Amy: You wanted me to have a boyfriend, mother, well here he is! Have to sign off now. My hunger for Sheldon is stirring in my loins.
Sheldon: Oh yes. It's time for me to make love to your daughter's vagina.

Sheldon: We no longer live at 2311 Los Robles. We live at 311 Los Robles. [holds up number 2 fixture]
Leonard: You changed the address on the building? What about mail?
Sheldon: No worries. I explained our predicament to our letter carrier. He was sympathetic. His exact words were, "Got your back, Jack. Bitches be crazy."

Sheldon: Proxima Centauri's the nearest star. The celestial bodies that follow are:
Alpha Centauri A, Toli, Barnard's Star, Wolf 359, Laland 21185, Sirius A, Sirius B, BL Ceti, UV Ceti, Ross 154, Ross 248, Epsilon Eridani, Lac 9352, Ross 128, EZ Aquarii A, EZ Aquarii B, EZ Aquarii C, Procyon A.
Those are the stars that are nearest to me,
Tra la la and fiddle dee dee.