I love the books so much more, of course, because by the sixth book there is just too much to cover and I think the fourth and fifth movies did a good job with it, but they in no way replace actually reading the books. Which I think is true of all books to movies (Actually, can anyone name a movie that was better than the book? Maybe the Ten Commandments? harhar).
I came at the Harry Potter books late because I tend to shy away from books with such intense popularity. Not for any reason other than I have a SLEW of things to be read and I hate to see amazing books overlooked because they were printed the same year of Harry Potter. Or Twilight (the first book I think is great, but I read it before the craziness).
But Harry Potter continues to be among my favourite books for kids and teens. And I particularly love books 4 through 7. They are dark and smart and uncompromising; I mean, JoRO kills off HEDWIG! "Grow up, Harry, life is change". Awesome.
I have heard that new generations of kids around 10 years old are being introduced to Harry for the first time. Their parents have decided to introduce each book every year. And for a good reason! Even if a 10 year old is a fantastic reader, much of the emotional depth of the later books will be lost on them. But, I believe that every kid this age should have read the first two books in the series. I believe that the Harry Potter books have done an amazing job of keeping kids reading. Seriously, if there is a kid out there who hasn't read the first book, pass it along to them and stand back.