Don't know if you people want to hear this or not, but I didn't enjoy the books or the films.
Compared to the authors I normally go for, I found J.K.R's writing a bit simplistic and not really captivating. I kept on waiting for something really exciting to happen in the first book; so you don't want to put the book down; but it just didn't happen. It just seemed a bit obvious, like I knew what was going to happen before it did.
As for the films, I found the first the first one quite boring, apart from the quiddich (sp?) and fell asleep during the second film. Haven't seen the others.
It is a good and original idea, but like a lot of other fantasy titles (Eragon for example) that are too obvious and unsurprising!