First came the Chris Columbus versions. Everyone seemed to like them at the time, although there was increasingly vocal dissatisfaction as time went on, followed by at least some backlash-to-backlash praising Columbus for putting so much in place: the set design, the world of the film, the story set-up, and most importantly the kids; he labored to get Daniel Radcliffe and Rupert Grint and Emma Watson to pay attention for just two minutes goddammit so that we might enjoy their fuller teenage performances late. And lo, that totally happened. There are good things in Sorcerer's Stone and Chamber of Secrets, much of which are even better when more inventive, less schmaltzy directors took control of the stories later on. In many ways, the Columbus Potters are some of the best movies he's ever made, by sheer virtue of being about charming wizard children rather than affluent and cloying suburbanites, but his leaden touch with adaptation (keep as much as possible!) and sentiment (but add a six-hour standing ovation for Hagrid at the end of book two!) render the conventional wisdom that his entries are the weakest dead-on.
Newell is a journeyman director in the best sense, able to move between genres with skill, and in his Potter entry, he brings skill sets acquired for Four Weddings and a Funeral (relationship comedy as the Hogwarts kids get flustered about hormones) and Donnie Brasco (ok, maybe that's a stretch, but the seriousness of the movie's final stretch is key). It helps that the book breaks from Potter formula in a significant and movie-friendly way.
David Yates took over for Order of the Phoenix, and won custody of the series through the end (in watching the final three pre-finale movies earlier this week, I had the odd thought that I was also watching the entire Yates feature filmography to this point, too). Order of the Phoenix, the only entry not scripted by Steve Kloves, actually does one of the better jobs of slimming down Rowling's sprawling, actually kind of movie-unfriendly narratives: the most bloated, overlong of her books became one of the shortest movies. Yates also brings style and adult sensibility to the series, continuing with Harry Potter and the Half-Blood Prince.
But as strong as Yates has been, there's also a bit of servitude to his work: a loyalty to the material and the fans (and, presumably, the studio) trumping any personal vision he might have for Harry Potter. It's respectable, often excellent, but I wish the filmmakers took more liberties with Rowling's structure, and admitted that 700-page books taking place over the course of a school year aren't an ideal blueprint for a movie's structure. Granted, the filmmakers often worked at a disadvantage, not knowing until partway during production on Movie 6 how Book 7 would actually end. But feeling the freedom to not just adapt each book one at a time, but actually re-arrange and tweak certain characters and plotlines, shifting them around as necessary and perhaps dispensing with the school-year timelines, might've made the movies' storylines flow a bit more naturally.
Maybe that's why I like Deathly Hallows Part One so much: finally, a Harry Potter movie that doesn't end on the last day of school! At first, I thought the splitting of one book (not even the series' longest!) into two films felt like both a cynical money move and an embrace of exactly what was wrong with many of the earlier adaptations: the feeling that if everything isn't included, then as much as possible should be (rather than making what's there make more sense). This still may turn out to be the case, but the extra room afforded Yates some leeway in how to tell his story; as a result, some of the dullest bits of the book (Harry, Hermione, and Ron hiding out in various forests and going on side investigations) are highlights of the film. There's a section of twenty or thirty minutes where Harry and Hermione are mostly on their own that contains some of my favorite filmmaking and character touches of the entire film series.
Splitting the other books and creating a ten or twelve-part movie series would've been indulgent, but Deathly Hallows Part One does show off the possibilities when you're not confined by what happens between page one and page million of a particular single book. I'm not sure if that'll turn Part Two into one long fireworks display—to my recollection, the split point chosen for Part One is further than fifty percent of the way through the book—but Part One, probably my second-favorite Potter film after Cuaron's, makes the Potter series feel rife with possibility one last time.