See also Textbooks on Various Subjects.
In recent times, I've warmed up to a variety of themes from history, philosophy, economics and technology. Here's a list books that have shaped my opinion, ordered by date of first publication. A modern version of the publication is linked to Goodreads when available.
Advice for a Young Investigator by Santiago Ramón y Cajal (1897; 2004)
High Output Management by Andrew S. Grove (1983; 2015)
A Farewell to Alms A Brief Economic History of the World by Gregory Clark (2007; 2009)
Making the Modern World: Materials and Dematerialization by Vaclav Smil (2013)
God's Debris: A Thought Experiment by Scott Adams (2001; 2016)
Infinite Powers: How Calculus Reveals the Secrets of the Universe by Steven Strogatz (2019)