Over the past year, I've been introduced to Mindware's Code Breakers. These are my latest, greatest math finds. The puzzles combine math practice and logical thinking all with bright colors. Win! I've used them to introduce advanced Algebra concepts to my children, and students in my math classes, in a simple, understandable manner.
There is a Level A and a Level B book. Each book contains 100 puzzles, but unfortunately I have found the books difficult to purchase lately. Occasionally they will pop up on Amazon, so keep searching if you're interested. (Or, if you know me well, perhaps I'll make you a copy.)