Oh, God, it's the Hogwarts version of Archer/T'Pol vs. Trip/T'Pol. 
From a technical standpoint (direction, cinematography, effects, etc.), I think HBP is probably the strongest movie yet. The adaptation was mostly really good, with some nice additions thrown in (I enjoyed the attack at the Burrow, and Slughorn's story about the fish). Daniel Radcliffe was excellent in this one; he really started to step up his game in PoA (thank you, Alfonso Cuaron), and he's continued to improve ever since.
It really felt odd that they cut out so much of the mystery regarding the Half-Blood Prince, however. Sure, in the book, there wasn't a lot there, either, but in the movie it was only mentioned offhand in a couple of scenes, and then suddenly Snape declares to Harry that he is the Half-Blood Prince, without any explanation as to why, or as to how he knew Harry was investigating that particular mystery.
I was also a little disappointed with Alan Rickman in the final scenes. Knowing what was going to happen with Snape in HBP, and knowing Rickman's capabilities, I was really expecting something fantastic in the final showdown. Instead, he came off like he was just sleepwalking through those scenes. I was hoping for a lot more.
Overall, I still liked the movie a lot, though I think I'd rate PoA and OotP ahead of it.

From a technical standpoint (direction, cinematography, effects, etc.), I think HBP is probably the strongest movie yet. The adaptation was mostly really good, with some nice additions thrown in (I enjoyed the attack at the Burrow, and Slughorn's story about the fish). Daniel Radcliffe was excellent in this one; he really started to step up his game in PoA (thank you, Alfonso Cuaron), and he's continued to improve ever since.
It really felt odd that they cut out so much of the mystery regarding the Half-Blood Prince, however. Sure, in the book, there wasn't a lot there, either, but in the movie it was only mentioned offhand in a couple of scenes, and then suddenly Snape declares to Harry that he is the Half-Blood Prince, without any explanation as to why, or as to how he knew Harry was investigating that particular mystery.
I was also a little disappointed with Alan Rickman in the final scenes. Knowing what was going to happen with Snape in HBP, and knowing Rickman's capabilities, I was really expecting something fantastic in the final showdown. Instead, he came off like he was just sleepwalking through those scenes. I was hoping for a lot more.
Overall, I still liked the movie a lot, though I think I'd rate PoA and OotP ahead of it.