Quixo
Quixo is a played on a 5 X 5 board, with 25 cubes. The object is to get 5 of your cubes in a straight line either horizontally or diagonally. You take a piece from around the outside, and then slide it back either opposite or at the end of the row. Simple rules, but not a simplistic game. Quixo has been recognised as one of the best games in both France and North America.
A video explanation of Quixo can be found here:
http://www.youtube.com/watch?v=eGtl_XG3×5w
Download the games rules (PDF)
Quixo Rules