GSN.com you can play all the free Mahjong games you want.
Mahjongg is a matching game like solitaire using tiles with chinese symbols. You move the tiles around the board to complete a match and eliminate them from the board. It is a good game to test visual and mental skills.
You can play alone or with others. Keep track of your score and compare it to other players. There are 5 versions of Mahjongg games at GSN - Mahjongg. Mahjongg Dimensions, Mahjongg Alchemy, Mahjongg Dark Dimensions and Mahjongg Toy chest - so you should find something you like.