I've just made a few purchases of math-related books:
Edward Frenkel's phenomenally good book Love and Math: The Heart of Hidden Reality is out in paperback, and I wanted to have it on hand. I interviewed Frenkel about a year ago, after reading a library copy of the hardcover. I'd certainly add this if I were doing a new version of my 10+ most influential books, as it got me into learning and writing about math on an ongoing basis.
One of the first things I did in that direction, after reading Frenkel's book, was take Jo Boaler's class How to Learn Math: for Students, which was valuable for thinking about math education (the course had only a limited sampling of math), which I'm interested in as a personal and political matter. I've now ordered her book Mathematical Mindsets: Unleashing Students' Potential through Creative Math, Inspiring Messages and Innovative Teaching, and may review it at some point here.
Also ordered: Patterns of the Universe: A Coloring Adventure in Math and Beauty, which certainly looks interesting.
Recently finished reading: Finding Zero: A Mathematician's Odyssey to Uncover the Origins of Numbers, by Amir Aczel, which is a nice blend of math, history and travelogue, and involves searching for the first zero through South and Southeast Asia.
Current non-math reading: Destiny and Power: The American Odyssey of George Herbert Walker Bush, by Jon Meacham. Quite interesting thus far (I'm up to around 1960) and elegaic, with much of the world described seeming not quite as distant as the ancient civilizations described in the zero book above, but pretty distant nonetheless.