The biggest shame of the prequels: It was such a good idea, but it had horrible execution. It could have been a three-part new age sci-fi version of Citizen Kane with the right people, but since George Lucas hired a crew full of Yes-man employees, it took a dump on the original trilogy.
That's not to say everything about them is bad (Ewan McGregor was great as Obi-wan), but so much could have been better with the prequels.