Don't judge the books just based on the movies. That's just silly. Most fans would agree that the first two movies, while faithful to the books, were watered down for a younger audience. The last three movies were more mature, but left out many key plot points due to the length of the books. Anyway, you can't convey onscreen the way Rowling writes, which is really what makes the books so great,
I am a proud Harry Potter fan. I travelled three hours on Friday just to attend a midnight book release. You have to understand that I am an avid reader, and a speed reader too. It's rare that any piece of literature invokes this kind of devotion in me.
Millions of children and adults don't line up at midnight for books that are just 'average'. Fantasy is not a new genre, and nor did Rowling claim that is was. However, she has created an entire world in the books, one that is completely different from Lord of the Rings, Narnia, or any of the other popular fantasy series. Her ability to create a protagonist who has faults but yet is so relatable is amazing, and every one of her characters is so multi-faceted. I cried three times while reading book 7, and I NEVER cry at books. In fact, my favorite character dies in the book and I was sobbing uncontrollably for at least an hour. I had to put the book down and finish it the next day. It certainly says something for J.K. Rowling's writing that she can instill such devotion to a fictional character.