John Tierney writes about Martin Gardner, the great mathematical-puzzle writer. I went through a huge Martin Gardner phase in my misspent youth, as I suspect did many other scientists and mathematicians.
Gardner’s best known for his Mathematical Games column in Scientific American. When he stopped writing it in the early 1980s, the slot was taken over by Douglas Hofstadter. I loved Hofstadter’s Gödel, Escher, Bach (again, probably lots of scientists, especially those about my age, would say the same), but I don’t remember liking his column at all.
As long as I’m free-associating here, there’s one more author of puzzle books that I remember loving when I was a kid: Raymond Smullyan. He’s an actual academic mathematician (unlike Gardner), but I know him only as the writer of logic puzzles. See, for example, the Hardest Logic Puzzle Ever. For those who went through a Smullyanesque logic puzzle phase and remember some of the tricks, this puzzle is hard but doable. If you didn’t, then yes, it’s probably extremely hard.
Godel, Escher, Bach was one of my favorite books as well. I also liked Metamagical Themas. Both really got me hooked on the interconnectedness of it all. Interestingly, Hofstadter is now one of my colleagues :).