Howard: This isn't the reaction I expected when I told you I was gonna be an astronaut.
Bernadette: What did you think was going to happen?
Howard: Honestly? Sex.
Bernadette: Howard!

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Howard: I invented a game. Want to play?
Leonard: Sure.
Howard: It's called Emily or Cinnamon. I give you actual quotes I've heard Raj say, and you guess if he was talking to his girlfriend or his dog.

Bernadette: Does your mother call you every day at work to see if you had a healthy lunch?
Howard: My mother calls me every day at work to see if I had a healthy bowel movement.

Penny: Wait, what is going on?
Sheldon: In case you have forgotten, Schrodinger's cat is a thought experiment.
Penny: No, no, no, no, I didn't forget. Um, there's this cat in a box and until you open it, it's either dead or alive or both. Although, back in Nebraska, our cat got stuck in my brother's camp trunk, and we did not need to open it to know there was all kinds of dead cat in there.
Amy: Homespun stories, knowledge of physics and a bosom that defies it. You're the whole package, aren't you?

Sheldon: This will just take a moment, it's on a five and a quarter inch floppy.
Amy: A floppy disk?
Sheldon: Well, I started the list when I was nine.

Sheldon: [to Brent Spiner] You are now my mortal enemy.
Wil Wheaton: Don't worry it doesn't take up too much of your time.