The Alchemist by Paulo Coehlo. I've personally read this book 4 times. With each time I find new, somewhat hidden messages that alter how a person can view life and approach the cards they are dealt. The wisdom on each page emphasizes the need to listen to your mind, body and heart with everything you do. Life will pan out beautifully, and often unexpectedly, as you follow your dreams.
Tuesdays with Morrie by Mitch Albom. Albom uses this book as an emphasis on the importance of mentors. His mentor, a college professor, still impacted his life well after his higher education ended. The impact went as far as Morrie Schwartz' (the professor), last days on earth. Albom describes his visits with Morrie as a second chance at picking the brain of someone who had so much experience and knowledge to offer those who would listen.
The Five People You Meet in Heaven by Mitch Albom. The second Albom book on this list, but just as impacting as the first. Albom's main character Eddie dies in the midst of a town fair ride gone wrong, but it is his guide through heaven that is the tearful part. Eddie's guides are 5 people he met throughout his life that have impacted him in some way, shape or form. It shows the reader that at the end of the day, or life rather, you may not realize how someone influences you. Even if just for a fleeting moment.
The Art of the Sale by Phillip Delves Broughton. Don't let the title fool you, this "sales" book has lessons that can be applied to any and all aspects of life, including any profession. The full title "The Art of the Sale: Learning From the Masters About the Business of Life", gives a bit more insight on the books content, as it explains how sales tactics and effectiveness can be useful in your everyday life.
Monkey Mind: A Memoir of Anxiety by Daniel B. Smith. Dan Smith's account of his life consuming anxiety is hilarious yet core shaking. He's able to put his emotions and experiences onto paper in a way that gives readers hope that despite what life throws at you (physically or mentally), whatever that may be, there is a light at the end of the tunnel.