The Unexpected Hanging and Other Mathematical Diversions

This book is just a collection of some of Martin Gardner's Scientific American 'Mathematical Recreations' columns. In other words, it's pure gold.
I would read the back of a matchbook if Gardner wrote it, because I know that I would (a) learn something new and amazing, and (b) be engagingly entertained in the process.
If you like math, science, puzzles, and great writing, buy this book. And all of Gardner's others.

This is the fourth entry in the first complete collection of Martin Gardner's Mathematical Library covering the entire twenty-five-year run of his Scientific American columns. Oddly, the cover and spine have no indication of this ordinal or the count of volumes. It is not immediately obvious this is part of a set. The back cover does cite Don Knuth as saying that this material is “…always worth reading and rereading.” ... Gardner’s engaging explorations telegraph an awe of the beauty of mathematics making this collection a treat and a challenge for any mathematics enthusiast.

[See my entire review at MAA Reviews]

While also not as engaging for me as some of his other books, it was still fun. The bibliography is stunning - I do not know how he managed to not only read so much, but have access to so many rare sources in a pre-Internet age.