Meditations, by Marcus Aurelius. The private thoughts of the once most powerful man on earth, filled with interesting insights and ancient wisdom.
The Courage To Be Disliked, by Ichiro Kishimi and Fumitake Koga. Simple and profound viewpoints on a diverse set of subjects, with the ability to change core Intuitions in a potentially liberating way.
Einstein: His Life and Universe, by Walter Isaacson. Beautiful insights into an interesting man and life.