Below are some general thoughts on the movie that include spoilers. Although you can figure most of them out if you've seen episodes 4-6 if you don't want to know what happens then don't read any further.
SPOILERS
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Revenge of the Sith, hereafter referred to as ROTS really gives the various main Jedi characters a chance to show their skills. We saw Yoda fight Count Dooku in AOTC but that was just a warm up for the balls to the wall battle in this movie with The Emperor/Senator Palpatine/Darth Sidious. CGI Yoda is completely believable, and Frank Oz does his usual first class of job of providing a voice.
If you ever had any doubts about Yoda's power, ROTS puts that to rest. Even though he is defeated by Darth Sidious you know Yoda is the only Jedi who could have lasted that long in a fight. No, Yoda isn't killed (duh) but goes into exile after escaping Sidious.
Having said that, Darth Sidious is an absolute whirlwind of destruction in this movie! Once he reveals himself to be the Sith Lord it's all downhill for the rest of the Jedi. The sequence where the Jedi are hunted down and massacred by Clone Troops had me shaking my head with shock.
The key scene is when Mace Windu, along with three other Jedi (to include Kit Fitso from AOTC) go to arrest Sidious for treason once it becomes known he is the Sith Lord. Sidious kills the other three Jedi with his light sabre with relative ease. He seems to toy with Mace Windu in order to entice Anakin to help him and follow The Dark Side.
Sidious' manipulation of Anakin to bring him to The Dark Side was very well done. Rushed, but well done. He very skillfully maneuvered Anakin into a position where he would do anything to protect the one person he loved the most: Padme. Sidious convinces Anakin that only the powers of The Dark Side can prevent her death during childbirth.
Anakin spends the movie in a tight downward spiral, his focus is on protecting Padme, but his fear, his ambition in the Jedi Council and his vulnerability to Sidious are his undoing. He is utterly ruthless once he converts to The Dark Side and finally becomes Darth Vader.
Keep in mind that although he has been "reborn" as Darth Vader, he has undergone no physical change...yet. heh heh heh....
Obi-Wan's character also shines in this film. His Jedi skills are put to the test when he fights General Grevious - a cyborg with four arms...each holding a light sabre. Ewan McGregor does a good job in this film of giving us an echo of the Alec Guiness Obi-Wan.
Finally, the duel between Anakin/Darth Vader and Obi-Won is epic. You've never seen two Jedi fight so hard. It's all the more tragic since they were so close: master/padowan, teacher/student, brothers.
At the end of the battle when Obi-Won leaves Darth for dead his frustration and anger boil over in a very un-Jedi explosion of emotion. This was one of the few moments in the film that shone as far as acting and dialogue.
Darth's mutilation scene is tough to watch. It's the most graphic depiction of violence in the whole series. But...it provides an explanation for the Darth Vader we see in episode 4-6.
When Sidious rescues the dying Vader and begins the surgery to transform him into the Vader we all know, Lucas then juxtaposes scenes of Padme's labor. While Vader is "repaired", Padme gives birth to A New Hope: Luke, who is born first, and Leia, who is next. Padme christens the infants and we get to see them for a few minutes before Padme dies. She has lost the will to live after seeing Anakin convert to The Dark Side.
In order to protect the twins Yoda and Obi-Won agree that they should be separated. Senator Organa (played by Jimmy Smits) and his wife adopt Leia. Obi-Won takes Luke to Tatooine and gives him to Lars and Beru Owen.
The Vader transformation scene was pretty well done. When they finally put the breathing mask and helmet in place we hear the distinctive breathing sound....and you know the real Darth Vader has arrived. He only has a few lines after this, and James Earl Jones' voice was enhanced slightly to sound younger. It's still the voice of Vader though, and there's no mistaking it for any other. If you don't believe me then...I find your lack of faith...disturbing.

There's a lot of other things happening in ROTS as well. Chewbacca makes a brief appearance when Yoda takes some clone troops to help the Wookie planet. R2-D2 gets to kick some ass as well. Even though his memory is erased at the end we can see where he gets his "go fuck yourself" attitude that he displays in episodes 4-6. C3PO gets short changed, but this was a busy movie that focused on Anakin's fall so that was OK.
The ship designs look good too. We see an early version of an X-wing fighter, TIE fighters, Vader's shuttle, star destroyers and rebel transports. At the very end we see The Death Star under construction.
Jar-Jar Binks is seen briefly a few times. He doesn't die.

There are no Ewoks to be seen.

For you Wedge Antillies fans: there's a brief reference to him in this movie when Senator Organa gives an order to a "Captain Antillies". I can only assume this man was Wedge's father since he was part of the military loyal to the Republic.
Well, I'll shut up now. I may go see this one again since I'm sure I missed some things. Bear in mind this is not a complete review, just some thoughts. I may post again later.
I'm looking forward to other views as some of you are doubtless fans as well.
DP