Beckett: I love you.
Castle: Yeah, well you better. It's two weeks to the wedding and it's too late to return the tux.

Beckett: Castle, aren't there more important things than winning?
Castle: Oh, that's a notion created to comfort those who lose.

Beckett: I think catching killers is pretty extreme and then there's marrying you.
Castle: Ah yes, I admit I am extreme. Extremely handsome.
Beckett: With a high degree of difficulty.

A reigning champion unable to cope with defeat. That sounds familiar.

Because the second Harold sets foot in this place it's going to burst his little '70s bubble.

Beckett: I look ridiculous.
Castle: Ridiculously hot.

Beckett: If Hector's as dangerous as advertised this could get a little hairy.
Castle: Hairy's my middle name. That sounded a lot better in my head.

Beckett: Castle I love you but I will not marry you on a ride or up in space or on slide.
Castle: I bet Dr. Seuss got married somewhere fun.

The last thing I need is to watch someone from my past try to seduce my fiance while talking about the goddess that lives in her hooha

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.

Castle Quotes

Sometimes the hardest things in life are the things most worth doing.

Castle

Castle: How do you know when you're in love?
Beckett: All the songs make sense.