Personally, because of the failures of the first two prequel, in some ways for me ROTS is the worst of all six films. While some of the scenes (any with Sidious, the wiping out of the Jedi) rise above any sequence in the previous prequels, over all the writing and internal consistencies simply flail away at any semblance of plot. Of course, the film confirms what I’ve always felt in that the good guys are the Sith whom are the ones truly capable of bringing order to this Lucas-created universe. Of course, Luke in many ways is the fulcrum that will hopefully combine both the Sith’s passion and anger with the Jedi's marketing and missionary abilities. (Never really read the Star Wars books on the backstory so I imagine there’s some history and myths I might be missing.)
The plot consistencies are too much to take. Yoda says to Anakin death is it and to simply accept it, then all of a sudden he can talk with Qui-Gon (God why did he get wiped out in Phantom, just so Yoda can say that line about him?). Princess Leia tells Luke that she doesn’t remember much about her mother, however, we see her mother dead at the end of this film.
Lucas is a great businessman and creator, but as far as writing, directing, and editing, he currently cannot match Peter Jackson, Speilberg, or even a Brian Singer or Sam Raimi. The Clone Wars cartoon by Genndy Tartakovsky was far superior in terms of writing and editing and it also had direct input from George. Hopefully for future Star Wars projects that will continue to be the case.