Harry Potter and the Half-blood Prince
If the movie is going to keep the name "the Half-blood Prince" they could have done a much better job at including more that dealt with the mystery behind the title. Snape's confession to owning the title at the end was rather corny. Dumbledore's character was unimpressive as well, too many forced lines. Otherwise I thought this was a great movie. The director, David Yates, did a great job at showing the inner conflict with Malfoy, teenage romantic dramas, and the start of the search for the Hoarcruxes.
Even though this movie only received a PG rating, I thought it was darker than any of the other Harry Potter films. With the sixth installment proving that it can portray the darkness in the books with a PG rating, the only reason for giving two of the previous movies a PG-13 rating (particularly #4) was for the crass humor and language, not existent in the books.
Draco Malfoy's inner turmoil with fulfilling his task to kill Dumbledore was a very good representation of human beings innate desire to fight against evil. Draco may be quite obnoxious and idiotic, but he is not evil. We see a glimmer of his goodness in his inability to kill Dumbledore. Malfoy is too innocent and aware of what's right and wrong to let such a destructive decision tear his soul apart. On the other hand, you see his fear of failure and dread for what Voldemort will do to him and his mother if he does not succeed. In contrast with Draco Malfoy, Tom Riddle was evil and had compromised his soul at a very young age. As a result of Draco's hesitancy, Snape comes off as some sort of hero by keeping Malfoy from ruining himself by stepping in to complete the task himself.
The movie did an excellent job depicting the romantic awkwardness exhibited by teenagers. This lightheartedness did a great job at complementing the darker side of the story and providing some comic relief.
I've read some reviews comparing this film to the Empire Strikes Back of the original Star Wars Trilogy, it being more thought provoking and darker than the others. Some complain about the lack of magic in the castle (talking portraits, moving staircases, etc.), the lack of a decent battle at the end. I, however, was rather impressed with the film and consider it my favorite so far.