Predictably Irrational by Dan Ariely
Mostly about cognitive biases. Helps you think better by knowing your shortcomings.
Whole Earth Discipline by Stewart Brand
About protecting the environment, but with interesting takes on nuclear power, GMOs, cities and slums, etc.
Good Calories, Bad Calories by Gary Taubes
Made me re-think a lot of things about food. Despite the "pop-science" title, this is a well researched book that looks at countless studies from the past 150 years.
American Prometheus: The Triumph and Tragedy of J. Robert Oppenheier by Martin Sherwin and Kai Bird
A biography of Robert Oppenheimer. Fascinating man.
The Blank Slate by Steven Pinker
A must read. Evolutionary psychology.