You know what I thought when I first met you? You were a mystery I was never going to solve.

Castle: This is so weird, I dressed up as him for Halloween.
Beckett: I did too.

Castle: Worried you can't control yourself when we're alone?
Beckett: It's not me that I'm worried about.

Castle: Thank you.
Beckett: Always.

I want you all to myself. If that makes me petty, so be it.

Castle to Beckett

Captain: She's like a tiger in there, I never get tired of watching her.
Castle: Me either.

He was out playing grand theft auto.

This looks like my first apartment, I used to have cockroach races.

This is why Alexis is never going to college.

Hurts like these take time to heal.

You're going to have to deal with mean, backstabbing girls your whole life.

Beckett: You had a lot of imaginary friends growing up, didn't you?
Castle: Still do.

Castle Quotes

I don't get it. He's into you and your determined not to give into these feelings that you clearly have for him. So he fantasizes about you through his writing. It is literally verbal masturbation.

Natalie

I can't tell you how many times I've had dreams of being on this very ship.

Beckett