I think I've talked on here before about how much I generally hate the Harry Potter movies, even though I love the books, even though I went to midnight release parties for the last three books (I got interested in the series the summer Goblet of Fire came out). Most of them have been pretty terrible. Although the casting has been terrific, they cut out all the wrong things. I knew we weren't going to get along from the first movie, when they eliminated Hermione's hero scene, where she solved Snape's logic puzzle.
I hated how in the third movie, he figured out the Patronus spell right away. It took him most of the term in the book, it's like an eighth grader trying to calculus, and it took away from the psychological journey of it all, because that was the book where he had to confront what happened to his parents and decide how it would affect the rest of his life.
In the fifth movie...I don't really remember the fifth movie.
In the sixth movie, they actually cut out the fight scene back at the castle following Dumbledore's death. They had Bellatrix smashing shit in the Great Hall, which is totally out of character. Bellatrix is a sadist and a suck-up, and I always thought she was a bit in love with Voldemort. She's not the type to just break stuff out of spite. They didn't show enough backstory about Voldemort, and they cut one of the scariest scenes in the books, where Dumbledore drinks the potion and trips out and starts pleading with some unseen attacker and asking him, or Harry, to kill him.
But they finally got it right in the first part of HP7. They staged some stuff that just happens in summary dialogue, probably most notably the scene at the beginning when Hermione modifies her parents' memory for their own protection, editing herself out. The Death Eater's meeting is scarier onscreen than it is in the book. All of their interiors were terrific: the Burrow, Malfoy Manor, Bathilda Bagshot's home, the Lovegoods' house. Because there's so much travel in this one, they get some great exterior shots too.
I absolutely loved this movie, in fact, the more I think about it. Sure, there were some things I would have liked to have seen that weren't there, but overall, they made excellent choices about what to film and what to cut. The characters were more true to the books: Fred and George were funnier, Hermione seemed smarter and nicer, Ron was much more lovable. I actually think I'm going to see it again, and I've never done that for any other Harry Potter.