Movie Franchises based on a Book Series

Major movies based in a best selling book are commonplace and examples of this would include The Godfather, the Exorcist and many others. Movies based on a series of books are less common but in recent years there has been an explosion of movies like this, starting with The Harry Potter Series then the Twilight Series followed by Insurgent, and finally this Hunger Games series which has ended with the fourth installment The Hunger Games MockingJay Part 2. What is even stranger about this increase in movies like this is that they are all based on children's books and this is definitely something that has never happened before. Some of these movies have been good, as an example some of the Twilight movies and others its really been a mystery why they have been so popular. The trend now seems to be that if there is a children's book series that is popular that the Producers in Hollywood know that they have a "built-in" audience so many more movie series like this will be made in the future. All we can hope is that the quality of the stories are either good or great or at the very least better than what we have seen so far.