I'm sure there are those who probably won't agree with me but the best acting in Revenge of the Sith came from the computer generated Yoda. Out of the first three episodes, yes this was best, but the acting just sucked. Ewan was great, Hayden was just brooding and Natalie was on some bad soap opera.
I feel rather cheated. Freaking George Lucas took two episodes to get to the point where Anakin was at least with a woman. The Revenge of the Sith just completely jumped into hyperspace and forced Anakin's turn to the dark side with the utmost haste. I felt there needed to be more conflict within him.
I'm sure most would agree that Lucas tried to shove way too much into this last episode. The beginning sequences with Obi-wan and Anakin rescuing Palpatine was good. There was humor and action. There was a mission. After that, I really think the movie went down hill and didn't recover till the final confrontation between Obi-wan and Anakin. Though Yoda trying to kick Palpatine's ass kept me on edge, I'm not thrilled with the idea that Yoda feels so much like a failure he had to go into a self imposed exile.
So all in all, not my favorite Star Wars, not my least favorite. I am glad that Episode IV exists, or else I would be really irked that the series ended that way.