With that said, among the best non SW edits are ADM's unofficial extended editions, they are usually quite good. Usually his are good movies to start with though, he just reinserts the deleted scenes into the appropriate spots. ADM (ADigitalMan) has some true fan edits he has done as well, since he knows what he is doing when it comes to editing, you are probably safe with just about anything by him. Special projects like Jambe's Building Empire and Returning to Jedi, while more documentaries than fan edits, they are certianly some of the best things to come out of this community (both Star Wars related though). If you like Evil Dead, Ridgeshark recently released his Primitive Screwhead Edition of Army of Darkness. It is a more of an extended cut, but there is also a great deal of editing and other work that went into it. It is top notch. I know there are a few others I would like to mention, but I can quite think of them at the moment.
For it to be a good edit, the editor really needs to put their heart into it, as adywan has done with Star Wars Revisted. When people are editing movies that they sorta kinda liked, you cannot expect them to put that much love into their edit. You read the descriptions of many FEs and read the editor saying things like "I remember the first time I saw this dog of a film in the theater. I nearly puked! But what we should have now is something that might actually be bearable to watch."
To me those kinds of descriptions are like saying, "Well, here is a sake full of dog crap. I left it in the sun for a bit so it would dry out, then I went out and bought a bottle of cheap perfume and dumped it on it. I am actually quite pleased with the outcome. I feel like I have turned this piece of dog crap into something that people might not mind smelling."
Why waste your time on purfume coated dog crap when there are plenty of things in the world that actually smell good to start with?
I think the reason why some Star Wars fanedits come out as good as they do, is that it is something people really have a strong connection with. These guys editing Ep. I - III are not doing so because they want to show that they have such good taste that they can turn something bad into something good, it is because they know it sucks, but they have always wanted to like it, and since it isn't going to get any better on its own, they want to try snip it, beat it, cut it, mold it, into something that fits with the movies they love so much. They really put their heart into it.
With that said, I am absolutely certian there are some edits out there of films other than Star Wars that have had that kind of love and care applied to them. Those are the ones you want to find. I am afraid I gave up on fan edits in general (one or two still pick my interest from time to time) after having enthusiastically downloaded a few and been disappointed by some really akward editing choices, or just downright bad editing (much like your experience with that T3 edit). Here, http://fanedits.com/fan-project-list.cfm you can find a very helpful list of fan edits with some details about them. Happy hunting and good luck.