I love reading and I absolutely belive that reading can not only entertain you but also broaden your horizon. To read is to grow. Even a badly written novel can change your opinion or give you another point of view on life or simply improve your language by forcing you to think whether or not this sentence sounds correct :).
With all that said, I found this list of books that although not necessary extremely interesting to read can trigger your mind and make you think. So go on, give your bran some proper exercise – http://blog.mindvalleyacademy.com/living/top-10-life-changing-books.