Star Wars
I don't think it will win any Oscars for screenwriting, but it was a really good movie.
People complain quite a bit about George Lucas' writing and directing, and with reason - reportedly, the majority of his direction to the actors consists of "Again, but faster and with more energy." When he has to write dialogue, it is direct and necessarily drives the plot - little attention is paid to naturalism. Love scenes consist of "I love you so much." "I love you more." "I'm frustrated that we can't tell anyone that we love each other." [Actors make pouty faces.] Very good actors, under Lucas' direction, are stilted and unnatural, and mediocre actors can be painful to watch. The only dialogue that doesn't necessarily drive the plot is the "comic" relief of the droids, but if Lucas wrote the script, the comic can stay in quotes. I think both Natalie Portman and Ewan McGregor had some real triumphs of acting in this movie when they managed to break the barrier of direction and really emote sympatheticly. Ian McDiarmid (who played the emperor) was also really effective in the first half of the movie, but the charicature in the second half was mixed.
There. Now I've gotten the requisite "I'm grounded in reality critique" out of the way, and I can say what's really important.
The movie was great! Yes, the talking scenes were as annoying as they were necessary to understand what was going on, and Lucas himself seemed to say toward the end, "Now that the movie's wrapping up, forget the dialogue - they'll figure it out from the vignettes!" The digital characters are really improved - they look almost completely natural in their movements now. I found myself forgetting that Yoda, in particular, was only pixels, especially toward the end of the movie. The space battle in the beginning was incredibly complex; like Return of the Jedi, I got the impression the digital artists were just showing off. The action was great - the lightsaber duels were probably the best since Darth Maul (probably better, but Darth Maul was such a surprise).
I don't want to go too much further, because I may spoil something for someone who hasn't seen it yet, but I would say that Revenge of the Sith is in a close run for my second favorite of the dual trilogy, right up there with Return of the Jedi (The Empire Strikes Back, of course, remains unmoved in the number 1 spot). Seeing it in the theater a third time should probably cement its place, if I do get a chance to see it a third time.