This post was published more than a few years ago (on 2004-07-16) and may contain inaccurate technical information, outmoded thoughts, or cringe takes. Proceed at your own risk.
Like all the other reviewers have said, the first Harry Potter movie with an actual soul. Also the first one without John Cleese as Nearly Headless Nick (a relief, in as much as I love Mr. Cleese, that character was really annoying it its… well, lack of soul), and the first one that I got into so much, that it actually seemed too short. That may be because they cut so much from the book, and didn’t give us quite enough time to get it into our heads that this Sirius Black is one bad mofo before turning the tables on us. Harry’s ability to adapt to new information from a possibly unreliable source, in particular, seemed superhumanly fast.