I'm not the most avid reader, and while there are several more books I could recommendthese are the ones that come to mind first:
1. Creating a Bug Free Mind by Andy Shaw:
A book to come back to over and over. It contains many tricks for improving your thinking and getting rid of "bugs" such as fear, worry, grudges, regret, procrastination etc. I'm still free from all these, but I'm a lot further down the road, thanks to this book.
2. Why Nations Fail (forgot the author)
A very interesting book, laying out the theory that stable, open societies will always triumph over corruption and dictatorship. It lays out many examples from both modern and ancient history to support this claim, and is a real eye-opener.
3. Guns, Germs and Steel by Jared Diamond
Another book that really expanded my understanding of world history, and how natural conditions have influenced our history. The aim of the author is to investigate why, for example, the Spanish managed to colonize the Inca empire, and not the other way around. This book makes one rethink most, if not all, of what was taught in history class.
4. Moscow, I don't love you by Sergey Minaev
A mad rollercoaster of biting satire. The "protagonist" is a suitcase with one million USD inside, and we follow it as different people find it and lose it, showing the ugly side of Moscow in a way that makes you laugh like crazy, before choking on that laughter.