On Revenge of the Sith
IMHO, Episode III is a pretty good movie. I saw it yesterday for the second time. I liked it more and not less upon second viewing. With Episode I, I really liked it upon first viewing, and then greatedly tired of it by fifth viewing. With Episode II, I never got beyond second viewing and the disappointments that brought. Revenge of the Sith, however, does deliver very well in the long second hour from the unmasking of Palpatine to the final duel between Anakin and Obei-wan. Very satisfying, for me, was how Episode III explains how the Jedi were purged and so realizes the "history" recounted by Kenobi to Luke in Episode IV. Honestly, at the end of the final duel, my eyes were beginning to burn. Coming out of the theatre, I felt a little of what I remember feeling coming out of Empire, a prescence I hadn't felt for a long time towards a Star Wars film: horror and pity.
The best line in the film is probably ". . . my little green friend."
Really, Episode III makes I and even II actually better films and makes the whole cycle greater than the sume of its parts. Especially in Episode III, we see people saying the same things or doing similar things to different people in different roles, so as to create a high degree of foreshadowing. Yoda says thing that would later be said by the Emperor, Anakin does things that would later be done by Luke, and Obei-wan does the same things twice towards different people in ways that mean opposite things. Whereas in other movies this would be banal ("Haven't we seen that before in another movie?), here, in the Lucas cycle, we are still watching what is, on many levels, same work. The director get away with what would otherwise be at worst plagarism or at best recycling.
A superb article comparing Wagner's Ring and Lucas' Star Wars may be found here. This is absolutely must reading for anyone who wants to understand the comp lit angles and "drama and society" implications of Star Wars.