So, included in my Brain Age game (for the Nintendo DS) was the game Sudoku. This is an awesome game and I have so much fun playing it that I didn't put it down for a week! I originally thought that Sudoku would be boring when I saw it at the bookstore and in the newspapers, but once I played it, I realized that Sudoku is a very engrossing game. There are alot of free games sites that you can find with Sudoku on them, like this one. There are many addicting games out there, but this is one of the best.