What If? Serious Scientific Answers to Absurd Hypothetical Questions by Randall Munroe
If you have been on the internet for a long enough time, you know the XKCD and Randall Munroe. And he wrote the book. Good one.
Just for Fun: The Story of an Accidental Revolutionary by Linus Torvalds and David Diamond
All my nerdy senses were pleased by this book. I highly recommend it.
A Philosophy of Software Design by John Ousterhout
The must-read for software engineers.
Thinking, Fast and Slow by Daniel Kahneman
Thinking, Fast and Slow - the most useful book you can read.