Man, I've been obsessed with Star Wars lately, for no reason at all. Watched all six movies back to back to back a couple weeks ago... I must say, while The Phantom Menace is pretty boring (save the ending for obvious reasons), and Attack Of The Clones would be a great movie if there was an option to just turn the dialogue off and only have John Williams' score, Revenge Of The Sith is legitimately a fantastic experience from start to finish. For six reasons:
1. The scene with Anakin and Palpatin at the opera. Very simple scene, just Palpatine telling Anakin a story. But brilliantly acted, and so much awesome foreshadowing.
2. That one scene where Anakin and Padme are looking at each other across the Coruscant sunset, with no sound or music whatsoever, right before Anakin goes and Makes His Choice. Beautiful.
3. Order 66. No elaboration needed
4. Related to Order 66, the scene where Anakin and the 501st invade the Jedi Temple and kill everyone, including the younguns. Brutal.
5. The Palpatine/Yoda fight, simultaneously with the Obi-Wan/Anakin fight, with the Duel Of The Fates and Battle Of The Heroes themes going full bore behind them. Epic.
6. Finally, the gradual appearance of various OT elements towards the end of the movie. The prequels took awhile but they finally started feeling like Star Wars movies.
ROTS is not without its flaws, of course, but it does so much right that I'm willing (in this instance) to overlook them.
That said, Empire Strikes Back is easily the best of the series, but that goes without saying.