Director: Alfonso Cuaron
This is an example of a very mainstream movie that crossed over to the art film crowd. Many people actually did not like this installment at all. They say it's "too dark," "it's not the Hogwarts I know," or simply "different." Well, thank God for that! Helmed by the great Alfonso Cuaron, this is the only one in the four Harry Potter movies so far that doesn't scream "franchise." It's also the only one that actually took me somewhere else and made me feel the magic of the series. There are many great scenes and indelible images in this movie that are simply unforgettable, like the hippogriff and when it took Harry on a trip over that lake, and when they did that time warp thing. This is a great movie and I believe it will stand the test of time.
(Speaking of dark sequels, all of you should really re-watch George Miller's criminally underrated Babe: Pig In The City. I loved it when I first saw it back in the '90s, and I remember it more than the original Babe, but many people hated it because it was such the opposite of its very cheery predecessor. It deserves a critical re-evaluation).