Totally Addicted :)
If you don't like a pairing in a book, you can change it around so that your favourite characters are finally together just they way you KNEW they should be, and even if it's something petty like you don't like the spelling of a name, you can change what you want, and thats pretty much what I think. :) Plus, if the original writers had half as many ideas as the fanfiction authors of today, we would have much better literature and movies than we currently do now.
I write, copy, save and read fanfiction almost every day of my existance. I copy other people's, and print it out so that I can read in the car, or when I'm going to bed or whatever. I love it so, so much, and I aim to write my fanfictions as better than the original story :)
I have written for Lord of the Rings, X-Men, and InuYasha. In Lord of the Rings, my fanfictions were more actor-based, but there were some book fiction, and character-based as well. Mostly I used original characters, which turned out to be Mary-sues, unbeknownst to me at the time. In X-men, I started to do pairings between my favourite characters. I did a few just regular, story-based, but most were Wolverine x Rogue (my favourite pairing) and then I did a story about Wolverine and Storm. With InuYasha, Most of my stories are oneshot. I have started a long one (not oneshot) about a pairing between Sesshoumaru and Kagome, and have finished many many relatively short oneshots, mostly about fluff between Rin and Sesshoumaru. I think so far I've done two about Inuyasha and Kagome, the second being about the triangle between Inuyasha, Kagome, and Kikyou. The Inuyasha genre is my current obsession, and I do confess that I am addicted. Oh well :)Now I'm updating, and I am writing for the wonderful world of Harry Potter. My favourite character is Professor Snape, and I'm working on a book-based story about a pairing between Snape and a character (hopefully a non-Sue) of my own making. I haven't decided what to call it yet, but it's coming along pretty well. I've read a few fic pairings between Snape and Hermione, but I've decided that's just weird and non-canon. But the best Harry Potter fanfiction I've yet read is called "The Moanings of an Overgrown Dungeon Dweller," by The Morrigan Three, and can be found on http://www.fanfiction.net.