I don't read much fanfiction, but some of it, when I venture in, is extraordinarily good. Good as literary pastiche, for instance. And that's a lot harder to do than it looks. Here's a paragraph some 'Rosencrantz & Guildenstern Are Dead' fanfiction:
"all things considered," guildenstern muses, "all things considered, in the world as we know it, with a death for every man who dares live long enough to meet his, whether it be by infirmity or by calamity, by malnourishment, by combustion, or by cardiac arrest ... all that behind us, or if you will, all around us ... i would say that we've done well enough for ourselves. our death is a formal one: death by announcement. death by the letter, on schedule, no shriving-time allowed, and it has for that a sort of neat inevitability, or, if you will, efficiency, that suggests before all else an aspiration to order. some people die in obscurity, but at least to be executed you first have to be named -- someone somewhere has to have judged you as somehow significant, if only significant enough to be killed. and what shame is there the being killed? even socrates was made to drink hemlock; even socrates accepted it, given his chance to escape. having, mind you, already quite surpassed the average life expectancy, but nevertheless. socrates."