I hope recommending other people's fic isn't against the rules here, because I would really like to rec an excellent RH fic that is not on LJ but on fanfiction.net only --
The Road to Redemption by Sarah Cartwright.
It belongs to a category that is automatically flagged as suspect for a lot of us, and with good reason: a Male Canon Character/Original Female Character pairing. However, there are exceptions to the OFC = Mary Sue rule, and this is one of them. It's basically a somewhat AU Season 3 in which, when Guy gains Prince John's favor in London, PJ also arranges his marriage to one of his cousins. The OFC, Rosalie d'Anjou, is a very well-drawn, three-dimensional character -- a young woman who is very vulnerable but also quite strong despite remaining (unlike Marian) within the boundaries of a traditional female role -- and her relationship with Guy does not suddenly blossom into a fairy-tale romance complete with mind-blowing sex five times a night. The portrayal of Guy is excellent, and the writing is vivid and sensitive. The other characters (Robin, Prince John, Allan, Much, Tuck) make appearances as well, and Kate, you'll be glad to know, does not. (Tuck already manages to be more interesting than he was in actual Season 3.) While I imagine the story will primarily appeal to Guy fans, I would recommend it to others as well. It's a WIP, on Chapter 13 so far.
Please read, and don't forget to feed the writer. ;) (Nope, I'm not getting commissions and the writer is not a friend of mine, I just love the story and think it deserves more exposure.)
NOTE: At the moment the story has been taken down for some revisions. I'll post a heads-up when it's back up.