The Harry Potter books are amazing. While Prisoner of Azkaban is no expection, it was my least favorite out of the series, which is why it only has 3 stars as opposed to the 4 and 5 stars I gave all the other books. 
 Update: Got around to re-reading this, and I enjoyed it a lot more than I did the first time around. I still stand by this being my least favorite, but I appreciate Sirius and Lupin a lot more than I did before. I also spent a lot of time rooting for Crookshanks to eat Scabbers because I knew this time around that he was actually Peter. This is really the last light hearted book left, as somebody dies in the end af all the rest of the books from here, so I don't despise it as much as I used to.