Fantastic question.
The selfish gene - for understanding human behavior
Meditations of Marcus Aurelius - for understanding how to be content
Debt, the first 5,000 years - for understanding money and finance from the ground up
Wright Brothers - for understanding how technological breakthroughs happen
Snowball (Warren Buffet), Andrew Carnegie and Rockefeller biographies - for understanding the mental mindset to win in business (it's not what you think)
Hackers and painters - for understanding startups and how/why they work
Zen and the art of motorcycle maintenance - for understanding beauty in the routine
Essentialism, the disciplined pursuit of less and Walden - for understanding how "stuff" gets in the way of happiness
Les Miserables - for understanding love
The selfish gene - for understanding human behavior
Meditations of Marcus Aurelius - for understanding how to be content
Debt, the first 5,000 years - for understanding money and finance from the ground up
Wright Brothers - for understanding how technological breakthroughs happen
Snowball (Warren Buffet), Andrew Carnegie and Rockefeller biographies - for understanding the mental mindset to win in business (it's not what you think)
Hackers and painters - for understanding startups and how/why they work
Zen and the art of motorcycle maintenance - for understanding beauty in the routine
Essentialism, the disciplined pursuit of less and Walden - for understanding how "stuff" gets in the way of happiness
Les Miserables - for understanding love