Episode III is better than Phantom Menace or Clones, or even both of them put together. But then, it was never going to not be - better by default, I guess you could say.
It had much goodness, but almost all of that goodness was founded in the simple fact that it was Episode III. What it lacked in pacing, plotting, acting and characterization it made up for in concept.
Here we see Anakin become Vader. In these films we find out much much more about Obi Wan. And Yoda still rocks, since by now he can jump, run, fight and dispatch guards with barely a glance. Yes, Yoda is a king among small green shrivelled aliens.
Plenty of saber action, too. That makes it all worth while because nothing with so many lightsabers can be all bad, can it? (Speaking of the sabers, check this out.)
As the movies draw to a close, I suspect this won't be the last we hear from a long time ago in that galaxy far, far away. With millions more to be made from the franchise, it'd be nice if they came up with something else with the quality of KotOR.