They're something I come back to every couple of years, there's always something interesting at fanedit.org.
Trying to download fanedits can be a stress though - they've been raided by dmca so they have to make it kind of difficult to get the video files.
The whole concept doesn't get enough attention imo. The idea of being able to modify something that the accountants dictated is really attractive.
I've always wanted to do a good edit of the Hobbit trilogy because it's so utterly bloated, but I think there's already some good edits out there by people with the same idea.
totally agree about the bloat, never felt the need to go back after the first marathon. ngl tho, I really enjoyed a 30 min edit of just the robot action from the first 3 transformers. what a wild ride.