While Mike Nichols two edits are the most famous fanedits of the Prequel Trilogies, they are dozens upon dozens of Star Wars fanedits and many of them push the level of improvement and visual quality far beyond what Nichols achieved. Most faneditors focus on the Prequels, but some have ventured into the Original Trilogoy. There are over 60 Star Wars fanedits, and they can be found www.Fanedit.org, which is a site where faneditors of all kinds of movies (not just Star Wars) come to discuss and list fanedits.
For a list of all Star Wars fanedits, their Star Wars page is a great resource. In the interest of full disclosure, I'm a faneditor who has released edits of Episode I: Shadow of the Sith and Episode II The Republic Divided, and have Episode III in the works.
There are many fantastic edits out there, with a variety of approaches, due to the sheer volume of Star Wars fans out there with their own visions of how to improve the Prequel Trilogy.
Regarding your follow-up question about how Fanedit.org rates fanedits; the basic process is that anyone who has an account on the site is able to rate the edit (on a scale of 1-10 stars) and are encouraged to provide a written review. First time editors must have their first edit 'approved' in order to be formally listed on the site.
Reviewers are encouraged to evaluate the edit on both technical merit (are the edits seamless or jarring? Is the audio smooth or abrupt? How does the video quality compare to the original etc..) and terms of story (did the editor improve the story/film-watching experience? Did they try something bold and original?)
Currently the site does not provide a side-by-side comparison of each set (all Epiosode I edits, all Episode II edits etc) but there is a greatest Star Wars fanedit page, all edits on this page have received at minimum 5 votes averaging 8.3 or greater, or at least 10 votes averaging 8.0 or greater.
Due to their fame and history, Mike Nichols edits have the highest score of any traditional style edit for episodes I and II, although most familiar with the full spectrum of SW fanedits will admit they are both outdated, particularly Episode I, plus many gripe about his non-cannon style opening crawl which is a letter instead of a set-up.
Excluding Mike Nichols' work, these are some of the top rated for each episode:
- Attack of the Federation : 8.76 (by faneditor JasonN)
- Shadow of the Sith : 8.47 (by L8wrtr)
- A Vergence in the Force : 8.08 (by ADigitalMan)
- The Republic Divided (by L8wrtr) : 8.82
- Attack of the Clones - The Spence Cut (by Spence) : 8.6
- Path to the Dark Side - The Diamond Cut (by Diamond Wan) : 8
Three edits deserve extra special attention in my opinion:
War of the Stars: A New Hope Grindhouse by The Man Behind the Mask (8.79 score). This is a mind-blowing edit of Episode IV. It is the most original, outlandish and bold version of Episode IV. Incorporating deleted footage, alternate sound sources and alternate angles, it creates Star Wars as you've never seen it.
Star Wars Episode IV A New Hope Special Edition Revisited by Adywan (9.93 score). This stunning edit of Episode IV took years to complete and seeks to address the staggering number of flaws that Lucas didn't address in his special edition. From color timing to improved special effects, once you watch this, it becomes your 'go-to' version of Episode IV.
Attack of the Clones: Super 8 cut by Rogue-theX. (9.27 score). Attack of the Clones in 34 minutes, as if it were a super 8 cheap cut of the film. Fun, fast and original.