Now this work of J.K. Rowling's takes on at least 3 forms. Books, Movies, and Games. Please try to keep these distincions.
The books, all that I've read to date, have been good. I'm currently rather dissapointed in the fantasy novels in general, having read all the ones I can even tolerate. The Harry Potter books have a new and engrossing storyline with a sense of humor that can satisfy the more adult readers as well as younger audiences. I like 'em.
The movies, well, they suffer from the common theme of any book made into a movie. Things get left out. Now, by themselves, they are ok, more geared towards the younger audience, so good stuff to take your kids to. Adults without kids, take it or leave it.
The games, ok, I've only played the PS2 game, and MY GOD, what a piece of garbage. I only have it because of my 7 year old kid, I SWEAR. It leaves out MASSIVE amounts of stuff, from the movies and the book, is badly written and programmed, and is a general waste of time and money. The Chamber of Secrets doesn't even have Dobby! You don't stab the Baskalisk with a sword, your sword shoots lightning bolts! WTF! The sword doesn't do that! Just GODDAMMNIT! *gasp gasp gasp* It basically sucks hairy goat balls.