Nixea, are you a former LOTR slasher?
Oh, I remember the days of elfhood, and Boromir/Faramir, and highly anatomically unlikely couplings between hobbits and men....
Agreed that amidst the hilarious dross, there are some good fan fictions out there, though it's years since I even looked. For instance, the Harry Potter fandom was completely bonkers, but there's a rather good novel-length fanfic called 'Chaos is Come Again' set in a dystopian version of the HP future, in which there is forced marriage among Purebloods to stop them dying out. It's Snape/Hermione.