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: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

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."

Leonard: Have you considered telling her how you feel?
Sheldon: Leonard, I'm a physicist, not a hippie.