Azkaban: My favorite, the most well made out of all the movies. It actually felt like a movie, everything sat well in it, it just felt RIGHT. Also, Cuaron is the only director who was able to keep Michael Gambon (Dumbledore) in check. Gambon turned into a psychopath after this movie.
Goblet: I hated this one the most for a long, long time. Just bizarrely directed, (Angry abusive Dumbledore WTF) and the acting all over the place. Putting the whole series into perspective though, this one is a bit charming. Also Voldemort's entrance was well done.
Phoenix: Eh. Stale, humorless, Yates can't direct, I'm sorry :-/ Fucked up my favorite 2 scenes in the ENTIRE book (Dumbledore escaping his office, and Dumbledore dueling Voldemort). They messed up the final duel so bad. In the book, Dumbledore knows he's fighting the most powerful dark wizard on the planet, and he's fearlessly speaking to him like a person, and fighting him at the same time, KNOWING he can't kill him. It's fucking incredible. And in the movie it's just a bunch of nonsense magic and grunting.
Half Blood Prince: Awful, joke of a movie. Beautifully shot, silly acting. Dumbledore still silly and unlikeable. Snape is merely a small, small part of this movie. And if you know the books, it's unforgivable how little attention they paid to him, considering, well... spoilers.
Deathly Hallows 1: FINALLY, HP getting his groove back! Excellent first half! Holy Scrambling to Tie Loose Ends We Neglected for 6 movies, however, Batman.
Deathly Hallows 2: Bullshit. Every single important scene ruined. Every other vital scene not even included. Just awful. I will never watch it again. It's honestly as if they have NO idea what was important to this series.
The thing that made the books so good was that they were about the characters, more than anything. They were so beautifully and vibrantly fleshed out, and when certain characters went head to head (Snape & McGonagall, McGonagall and Umbridge, Dumbledore & Voldemort) fucking sparks flew. Rowling is a fantastic writer, I don't care what anyone says. Her characterization is up there with the literary greats. And the movies after #3 just shat on all of it, and made these boring, washed out, decent special effects shows. Adult actors get minimal screen time, and when they do they chew the dialogue so hard it's just silly. Anyway, yeah, Harry Potter. fav book series of all time. I apologize for this rant.