Harry Potter's third adventure is easily my favorite.
Alfonso Cuaron took over as director, and he was an interesting choice. That he started taking things in a new and more serious direction was also a good thing.
Potter's third year at school is overshadowed by news that a wanted criminal associated with the death of his parents has escaped from an infamous magic prison, and that Harry may be his next target as a result. This also involves the (literal) soul sucking guards of said prison being employed to stand watch over the school. But Harry doesn't have to go it alone. As usual, his loyal friends Hermoine and Ron are there to help him out as he tries to deal with this looming news as well as further uncover the mysteries of his past.
I loved how drastic of a turn this one made from the last. Sure, it's not completely serious, but having it start to get that way is quite refreshing. This series has always had some good art direction and set design, but Cuaron really delivers the goods with some quite moody, eerie, and atmospheric stuff.
The effects are good as per usual, the music great, and once again, the core cast provide great performances.
Definitely check this one out. It's quite a ride.