Harry Potter and the Half Blood Prince

I'm not going to bother with the plot, you're either on board at this point or you're not. Here's a few thoughts:

1) This is the first film of the series where I could see someone who hadn't read the books getting a little lost in parts. I really don't think this is that big of an issue since at this point you have to figure that everybody who's going to be on board is already up to date with all incarnations of the Potter mythology (including fan fiction that depicts Harry hooking up with Ethel Merman). The filmmakers aren't trying to convince new people to see this, they just need to keep the true believers happy - something in which they largely succeed. Yes huge chunks of the book are cut out (necessarily so, I believe this tome clocked in at roughly five thousand pages) but they hit all the high points and move the story along well. Really I have to say that they filmmakers have actually done a pretty good job with the entire series keeping true to the spirit of the books, while still making fairly entertaining stand alone films. This is a harder task than it appears (given the dramatic failure of most book adaptations) and even though they're helped by strong source material that's no guarantee that it will translate into solid film making (see the Narnia films for exhibit A).
2) Ron has been successively marginalized in each film to the point of just having him sitting on a curb while Harry and Hermione make the big plans at the end of this one. I understand that the filmmakers can focus on only so many characters at once (and I think they in general picked the right ones), but they might want to think about making Ron have more to do than just wander around acting like somebody who just fell off the short school bus since he's so prominatly involved in what happens.
3) For some reason they decided to turn Dumbledore into Shecky Green (timely reference, for the kids). While the character always had a subtle sense of humor in the earlier installments, in this one he's constantly firing off one liners like its Late Night at the Apollo. It wasn't necessarily unfunny but felt like a wierd tonal shift for him.
4) The film does play up the raging hormones and adolescent romances of the characters more than the book did, but thankfully it doesn't cross over (much) into creepy/annoying territory. Given that this is an area that could have been handled horribly I'm happy that it came off as light as it did. Still the sexual tension between Ron and Harry could have been dialed down a bit.
5) The above criticisms are rather minor. This installment kept up the momentum of the previous films, and I look forward to what they do with the final two films. It also made me want to go back and reread the last book just to remember what happens next (how's that for mixing tenses) which is a good sign. Of course these aren't necessarily great films, but they're solid and infinitely more watchable than much of the other fantasy dreck aimed at similiar demographics (Twilight I'm looking at you).