Good idea. I think I was starting to take over the movie thread too much, lol.
There is a lot of good stuff in the third movie, particularly the artful visual presentation and the lovely music. But I can't consider it one of the best movies because they completely chopped out all explanation of who Moony, Wormtail, Padfoot, and Prongs actually were, why they made the map, why Snape hates Lupin and Sirius, how Sirius escaped from Azkaban and how he identified Pettigrew as Ron's rat, and why Harry's Patronus looks like a stag. I know it's a lot of information to present, but chopping it completely wasn't the answer, because without it the plot simply fails to make much sense at all. Also, Hermione's characterisation is bordering on Mary Sue-ish at times, misrepresenting her actual personality, in part because any reference to her extreme stress at going back in time over and over to take so many classes was simply removed altogether. Having her be the one to say "If you want to kill Harry, you'll have to kill us too" is just the last straw, because in the book this line was spoken by Ron, signifying his bravery and loyalty even with his broken leg, while the movie just makes him look fearful and goofy.
Pretty much all these mistakes are at the screenwriting level, and it's annoying because Prisoner of Azkaban is my favourite of all the books in the series, being the best written and most emotionally meaningful and nuanced. Still, at least the music is so damn good, and the casting and so forth are splendid.
Of course, the third movie looks like writing gold compared to the fourth, which is a choppy mess whose plot ends up making even less sense from having a huge amount of essential material removed . . .
My association with Harry Potter goes back a long way--read the first four books in just a few weeks about ten years ago (I was 16) as a deal I struck with my sister; I read them in exchange for her reading Lord of the Rings. At first I was sceptical they'd be any good, but I'd already fallen hard only a few pages in, and it got even better as it went. It was tough waiting three years for the fifth one to come out, I can tell you!