Bernadette: Oh, boo-hoo, you're not going to space!

Howard: I'm sorry I didn't take you to the airport. I just want you to know I'll never forgive myself for being so selfish. And I promise to keep you close for the rest of my life.
Bernadette: Oh, no, that thing's gonna end up in my bedroom.

Bernadette: Gosh, Amy. I'm sensing a little hostility. Is it maybe because like Sheldon's work, your sex life is also theoretical?

Bernadette: (Shouting from the bathroom) How many times do I have to tell you to replace the toilet paper when it's empty?
Howard: I'm in the middle of something.
Bernadette: So am I!

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.