>>211390482 (OP)The best HP books are Prisoner and Half-Blood Prince
In prisoner Rowling fully settled with her style, characters, world etc, and plot is pretty fresh after two books with the same "secretly bad guy in hogwarts who has to be stopped" premise.
And Half-Blood Prince is the most meaty and interesting story wise and character wise as it's focused on the major and fascinating characters like Dumbledore and Snape, as well as Voldemort himself, it doesn't have the massive filler of Order of Phoenix, it's very well written and edited.
As for the weakest books, I think that would either be Deathly Hollows for how crammed it was and how out of left field Deathly Mcguffins came, or first two books, that are very much kid ones and Rowling tried her hand there.
Goblet and Order are an overall in the middle of the bunch. Order suffers from bloating but is fun and nice to lose into, this is like the whole huge attraction for a reader, because Rowling has good prose and makes it interesting as well.
Goblet is also good, but just can't compete with the Prisoner and HBP.
So in the end it's
>Half Blood Prince>Prisoner of Azkaban>Goblet of Fire>Order of Phoenix>Chamber of Secrets>Philosopher's Stone>Deathly Hallows.