I don't understand the extreme fandom for HP, neither do I understand the extreme hatred from the opposing camp. The books are terribly well written, the plots are well thought of, with a few glaring mistakes and obvious references to LOTR. The series has a few smart tricks up its sleeve, and got a lot of people to take an interest in reading. By modern contemporary standards, it is an excellent work of fiction, showing the world that a lot of money can be made from writing. The death bit was well... done to death, but otherwise it is a pretty interesting read.
Though not the best fantasy series around by a long shot, definately one of the most widely recieved.