OK here are my top 5 -

- Mindset, Carol S Dweck - if you told me I had to narrow it to one, this would be it

- Principles, Ray Dalio

- Relentless, Tim S. Grover

- Man’s Search for Meaning, Viktor Frankl

- The Power of Myth, Joseph Campbell

Honorable mentions - Anything by Simon Sinek, Jocko Willink, Ryan Holliday, David Goggins