That's a good question, I guess it just depends on your preferences. It's a Dystopian Science-Fiction novel, so it's set in a future time period. I've heard people compare it to The Hunger Games before, though their stories aren't very similar. It does a great job of illustrating the bad side of human nature, and in the book, the author does a great job of grabbing the reader's attention and immersing them into the story's setting.
The movie misses a few important events from the book but it still does a decent job of representing the story. If you have the time, I'd encourage you to read the books so you can compare them yourself, but either way it's still fun to see the film.
If you haven't heard what Divergent is about yet, I'd be glad to tell you that too.