Mahjong Solitaire. I'm mildly addicted....
I used to play Scrabble on Facebook but it got too cut throat and nasty - other people were taking it much too seriously for my liking and I just wanted a light hearted game. So I stopped.
Mahjong Solitaire is my favourite too. I also played scrabble years ago with an on line partner who lived 2 suburbs away, never met him but we played well together. On the rare occasions we played with others (they tended to be USA players) we too found them to be too competitive when we just wanted a fun game so gave that away,
I play heaps. Mostly word games plus mah jong, hidden object, peggle, chuzzle, bejeweled. I have about 15 on my pc at present and I play free ones at pogo and other sites. Keeps the brain nimble. . . apparently. LOL