There have been many problems with the previous HP movies (specifically, they tend to add a lot of bullcrap that never happened in the book and has no need to be in the movie). This one (with one exception) didn't do that very much. They had to leave out pieces, but (with one exception) they didn't leave out anything too significant. It may not have been ver batim to the book, but I'm quite sure that it did the most justice to the original of any of the other movies. Besides that, it was a genuinely good movie. Great comic relief, good special effects (the quiddich players don't look so much like video characters anymore) and the end provides good catharsis.