(Note: This shouldn't be too much of a spoiler, but still... if you haven't read the books, well, you deserve what you get.)
The movie was awesome. There were still a lot of battle scenes, but I enjoyed them a lot more than in The Two Towers. The scenes with Gandalf riding out to meet the Nazgûl and with the Rohirrim gathering to charge the orcs outside Minas Tirith were especially powerful. (Minas Tirith was beautiful, by the way.) I also really appreciated the views of all the cool creatures. The Mumakil and the winged steeds of the Nazgûl were particularly awesome. There were also some shots of cave trolls, a warg, and some giant mutant rhinoceros sort of things towing a siege tower. I liked how the lead orc was white, in a sort of visual parallel to Gandalf the White.
As for things that were left out, well, the obvious one was their last adventure returning to the Shire. I kind of expected that, but I was still a bit disappointed. No, it probably wouldn't have fit within an accepted flow of action for a movie, but if it was good enough for Tolkein it would have been really cool of them to have taken a shot at it. Oh well. Overall, I thought it turned out quite well, so I'm happy. Go see it.