The prequels could have been good movies if they were done properly... they really weren't. Episode 3 was almost getting there, and a complete improvement over the other two... the first one was a mess, and it really seems that half of the time they spent establishing Anakin's character DIDN'T need to be wasted. It would have been better had they started off with establishing Darth Maul, and then getting to Tatooine and starting up on Anakin halfway through the movie. Plus, there was no call for the Gungans to take up THAT much movie also.
The second was better, but bad dialogue heavy, and the third tried very hard (but not hard enough) to become just as good as the originals. Again, I say he needed a pinch director or someone to bounce ideas off of. Empire Strikes back WASN'T directed by him, and that was considered the best of the series. Looking how great a job Genndy Tartikofsky did with the 5 minute Clone Wars cartoons (I only say the movie version of the CGI one... I kinda dug it), the ideas were there, but they were doomed to bad execution.