I like fanfiction. You get a fun and interesting story, but with characters you already know and love! Sure, some are pretty badly written, but quite a few aren't. I even tried writing my own, but I'm pretty sure it falls under the "pretty badly written" category. I used to read fanfiction quite a lot in my youth, but lately I haven't read it at all as I have moved over to doujins. Still, love the concept, think it's great writing practice.