Popular movies based on books (Harry Potter is a great example)

I dislike movies based on books. I always feel like I'm missing out on at least 50% of the book's story, because of how rushed the story seems in the movie. I get that feeling regardless on whether I've read it or not, so I'm disappointed pretty much all the time.

I personally think this "Movies based on books" trend needs to stop. A tv series adaptation would work much better, since their would be a hell of a lot more time to cover the story. Kinda like what Japan does, with them having anime adaptations of their manga series and light novel series.

They're not based on cartoons. They're based on their comic book series.