As much as I love math, I never got into soduko. However, I love those division problems that use letters to represent the numbers. But they don't make a book of those.
I like the point and solve crossword puzzles, but have only found one book like that. So I waste my time away with the variety puzzles. One type of puzzle makes me bored, I need the variety of Acrostics, Cryptograms, and such.