I was satisfied with Revenge of the Sith. It was certainly the best of the three prequels, and that by a long shot. It was probably better than A New Hope and Return of the Jedi, too. George Lucas toned down the cheesiness present in the first two prequels considerably. Sure, there were a couple of things that made me cringe, including the last scene with Vader and the Emperor, but all in all, the movie was appreciably more grown up. I guess that's more appropriate, in keeping with the themes of this installment, but I wish all three of the prequels would have been equally no-nonsense.
One thing I can't get out of my head (and why I'm posting even though it is nearly 1 AM and I have to go to work tomorrow) is how overtly political Episode III is. Emperor Palpatine has consolidated power in the Executive (USA PATRIOT Act?), has a blinded, fawning legislature (Congress?), controls the courts (see the current dustup in the Senate) and is engaging in a trumped up war to shore up his popular support and "bring peace" to the galaxy (Iraq, duh). Darth Vader even tells Obi Wan "If you're not with me, you're my enemy." And finally, Obi Wan tells Vader that his absolutist worldview will lead to death and destruction. I really have a hard time coming to any other conclusion that Lucas had this all on his mind while writing the movie.