Castle: The killer can't be a ballet dancer because it'd just be such a huge let down.
Beckett: Of course, we can't let facts get in the way of a good story.

Castle: Our killer is a ninja.
Beckett: Or he is just an athletic person with a hooded track suit.

Castle: See what happens when I leave you alone.
Beckett: Babe, I wasn't alone. When they were interrogating me, the only thing that kept me going was thinking about you. About our future, the wedding. You were with me the whole time.

I need you to know that our partnership, our relationship is the greatest thing that has ever happened to me. You are an amazing man and I love you with all of my heart. Always.

Capt. Fowler if you can hear me this is seriously interfering with my dinner plans.

Because it's clear to me that what we both need is a really good font.

If I have to hear that confession one more time, I'm going to shoot somebody.

Dwight: I need to confess.
Beckett: Yeah, take a number.

Castle: You should know it, you're engaged to a genius.
Beckett: Yes, a genius at annoying me.

I think we all just kickstarted our day.

Castle: Do I smell coffee?
Beckett: If you do, it was made by elves.

Castle: To the things we missed.
Beckett: And to those we didn't.

Castle Quotes

Beckett: Wait, there's a sex scene in the book? Between us?
Castle: There's a sex scene between Nikki Heat and the roguishly handsome reporter who's helping her.
Beckett: Oh, good. So he's nothing like you.

So how did she take it, us being together?

Beckett