What are the best motivational books?

Man’s Search for Meaning by Victor E. Fankl

Psychiatrist Viktor Frankl’s discusses in-depth his experience with living in Nazi death camps and describes the lessons it taught him about spiritual survival. Frankl puts forth a convincing argument that avoiding suffering isn’t realistic. However, through choosing how we cope with that suffering and the meaning we ascribe to it, we retain the ability to move forward with renewed purpose.