Amy: I'm in this relationship, too. I need to stand up for myself.
Leonard: Of course you do.
Amy: And if he doesn't like it, he can move back here.
Leonard: Oh, he can try. He'd just need a good locksmith.

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?

Sheldon: My mother was at bible study. I walked in the house expecting to find it empty, and I heard a sound coming from my parents' bedroom. When I opened the door, I saw my father having relations with another woman.
Penny: Oh, that's awful!
Sheldon: I know. It's also why I never open a door without knocking three times. I mean, the first one's traditional, but two and three are for people to get their pants on.

Sheldon: Being with Amy has awoken the sexual creature within. When I see a pretty gal walking down the street, I think, "hubba hubba" like any other guy.
Penny: You kiss your mother with that mouth? 'Cause it's fine.

Bernadette: Uh, I left my phone downstairs!
Howard: Damn, so did I.
Bernadette: Wait, I have my iPad.
Howard: What are you going to do, e-mail 911?