It is difficult to mention one book as there are quite number of valuable published books in different disciplinary. But If I am given only one choice then I will mention the book written by Steven Covey entitled "The 7 Highly Effective Habits ...".
In my earlier years '' How to stop worrying & start living '' & with the passage of time while my interest processed The Science of Astrology & subsequently following the path of philosophy , I have been immensely impressed by the book '' Autobiography of Yogi By Paramahansa Yogananda
Robin Sharma , " "Discover Your Destiny" with Monk who sold his farrari and Vivek Mehrotra , " Why My Horse Doesn't Drink" These books help people around the world live great lives.
Currently Reading Charlie Wilson's War. I wouldn't use it as an academic source, but its well written and provides rich contextual information on a series of historical events that laid the groundwork for the Taliban to grow to prominence and later, Al Qaeda.