If you like word puzzles, you'll twist and shout over "Sit & Solve Spiral Puzzles" by Byron Walden. Imagine a list of clues with a long string of overlapping answers, words going in both directions; now imagine that string spiralling around on itself. Got the picture? Once you get turned-on to these unique puzzles, you won't be able to put them down.
Byron Walden is a math professor at Santa Clara University. His puzzles regularly appear in the New York Times and the Onion.