The issue on some fan edits is that a bad film, is simply, well...bad. An edit can't really save it, because its problems go deeper than deleting scenes, rearranging scenes, etc. It goes deep into the plot, or lack thereof. Its hard to add plot by editing, remove a crappy plot, etc, by just editing.

A fan edit that I liked was Magnoliafan's Star Wars Episode 1. It made that flim better than before. I think it is avalable on torrents. The Phantom Edit is also good, but I personally perfer Magnoliafan's version.