The movie is beautiful! Hayao Miyazaki is amazing!! I would recommend it based solely on the fact that it's just beautiful! But the story is good too!
Plus Christian Bale shares his vocal talents to bring Howl to life. So you have a beautiful movie and a good story all brought to you through the extremely sexy voice of The Dark Knight himself!
But not only did I enjoy the movie, I just finished the book by Diana Wynne Jones. It was almost a completely different story, yet I'm not sure which one I liked better. Though I have to lean more to the book.