Regarding Castle fanfic; I've continued to read a lot of it in recent months, especially to cover the show's various hiatuses.
I can recommend most of the stories written by Cheerful Chemist. The writer has a good sense of story telling yet really likes to focus on the relationship building aspects.
Also there is an ongoing story called "Hi Dad", sorry I don't remember the writer, which allows us to see the growth of the Caskett relationship through interactions between Kate and her father. The writer has followed the couple from the series beginning to currently up to the beginning of this season. We see Kate talking to her father about Castle and we see him realizing how her attitude changes over the years. It's a fun series of one shot shorts.
Tank (who might just contribute to the Castle universe someday if he ever figures out how to get onto fanfic.net)
