I'd never read fanfic about certain books because I don't want really want anyone else's fingers on characters I love.

Good characters will carry me through an otherwise weak novel, whereas the reverse is almost never true.

I care enough to cry my eyes out when my favorites die, even if I've read the book before. I especially love a truly noble death, or one after having saved the world. Add some ghosts, a lot of dealing with the consequences of having made mistakes, throw in some heartbreak and I'm yours.