Last year toward the end of 2018 there was an awesome thread asking this same question. I personally found it very valuable, but have not seen one so far for 2019. I thought I'd get it started!
What were the best books you read this year? Preference to books released this year, but if an older book changed you for the better by all means please include it!
"Ask HN: Best books you read in the past decade?" https://news.ycombinator.com/item?id=21900498
"Ask HN: Favorite Nonfiction Books of 2019?" https://news.ycombinator.com/item?id=21792158
"Ask HN: What book(s) had the most impact for you in 2019?" https://news.ycombinator.com/item?id=21677320
"Ask HN: Books You Read in 2019?" https://news.ycombinator.com/item?id=21799531
"Ask HN: What were the best science fiction books that you read in 2019?" https://news.ycombinator.com/item?id=21925100