Harry Potter 3 onwards, they have basically just cock slapped the books from there on saying "You are more of a... direction to head in, screw your already established plot points and rules."
Prisoner of Azkaban, they break the no magic rule in the first 10 seconds of the movie ffs aside from that I have no complaints.
Goblet of Fire, no Dobby and a few other sub plots that made the book enjoyable
Order of the Phoenix, just about passable until they added to the narrative what they took away from it, Umbridge blowing a huge fucking hole in the room of requirement WTF
Half Blood Prince, EVERTHING