I loved it - that's not quite the right word for such a dark movie, but I don't know what else to say. It's rather disturbing. Vader is a real tragedy. Not that I didn't know it was coming, but I didn't know how. It's sort of weird to end a 28 year old story on such a melancholy note.
I will choose to believe that the Emperor is dead at the end of episode 6, because that's just a nice tidy way to end the saga. I'd rather not see it turn into a never ending story. I think. Maybe I'll feel differently in another 20 years when Lucas Jr. makes 7,8,9. I just hope they find someone who looks as much like Mark Hammil as Ewan McGreggor looks like Sir Alec Guiness.
This movie is obviously the best of these 3, and I agree with Kevin Smith's comments at the top of this thread. Bravo to George Lucas. I can't even begin to list all the things I liked about this movie, so I'll just make a few nitpicks.
I've made peace with the fact that either Hayden Christiansen and Natalie Portman are crappy actors, or their abilities were stifled and retarded by lousy writing/directing. I've accepted the fact that we are just not going to get believable romantic dialog out of them, and this movie is no exception. Oh well. But they did do a decent job of escorting Christiansen's character through his transformation to the dark side.
SPOILERS below...
Jar Jar's appearance at the end profanes an otherwise important scene. Was that really necessary George? I guess that's his way of saying "I'm the boss". At least he didn't let the toad talk.
Things that don't jive with the original series:
Anakin's voice is all wrong. How are we supposed to believe that he picked up an African accent after being burned? That's not really a criticism of ep 3, just a general comment. But it's too bad he couldn't have trained his voice a little deeper for this episode.
Obi Wan and Anakin are about a thousand times more handy with their lightsabers in their duel in ep 3 than 4 - understandible for the old and out of practice ep 4 Kenobi, but logic would say that ep 4 Vader would have ginsued old Ben in about half a second, judging from his mad skills in this movie.
R2D2 - somewhere between ep 3 and 4 he loses his ability to LEAP out of starfighters, spray oil slicks, catch objects thrown at him, and speed along at about 25mph. Huh??
At the very end of the movie where we see Vader and the Emperor in the imperial cruiser, all of a sudden we're back to 1977 spaceship control panel technology?
Clones/Stormtroopers - are we to believe that the troopers in ep 4 are a new batch of clones made from someone without the latin accent?
Anakin's head - We never see him get those huge lacerations we see when it is revealed in episode 6. And in ep 6 he's got eyebrows and very little trace of the severe burning he suffers in this movie.
But those things didn't make me enjoy the movie any less. I thought it kicked ass. I'm definitely going to have to see it again to absorb it all.