Leonard: Congratulations. Who would've thought you two would be the first in our group to start a family.

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. We are made of particles that have existed since the moment the universe began. I like to think those atoms traveled fourteen billion years through time and space to create us, so that we could be together and make each other whole.

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

Penny: This is why I've been saying we should keep champagne on ice.
Sheldon: Sarcasm?
Amy: Yes.
Sheldon: That was tricky because when it comes to alcohol, she generally means business.

Howard: How are the taxes going?
Bernadette: Okay, but you've got a lot of receipts for the Lego store in here.
Howard: Those are business expenses. You can write those off.
Bernadette: A $200 R2-D2 is a business expense?
Howard: Oh, Bernie, you're gonna have to sound a lot more confident when we get audited.

Sheldon: I'm exceedingly smart. I graduated college at fourteen. While my brother was getting an STD, I was getting a Ph.D. Penicillin can't take this away.