There is an american site full of great games, which I like to recommend to all of my readers. Its name is gamecolony.com
On gamecolony.com you are able to play for example gin rummy, dominoes, canasta lines and mahjong - the games you should already know from playok.com. A great option is the opportunity to participate in tournaments, where you have a chance to earn some money. After the US presidential election, the dollar will go up so it's good to have some of them in your pocket. :-)
If you want to try it, put the link below in your Internet browser.
http://www.gamecolony.com/?pal=daniucha
And here are some links to the most popular games at gamecolony.com
https://www.gamecolony.com/cgi-bin/rooms.plx?gameid=3 (gin rummy)
https://www.gamecolony.com/cgi-bin/rooms.plx?gameid=9 (mahjong)
https://www.gamecolony.com/cgi-bin/rooms.plx?gameid=5 (backgammon)
https://www.gamecolony.com/cgi-bin/rooms.plx?gameid=6 (dominoes)
https://www.gamecolony.com/cgi-bin/arc_trn.plx?gameid=21 (solitaire)
https://www.gamecolony.com/cgi-bin/arc_trn.plx?gameid=26 (lines)
https://www.gamecolony.com/cgi-bin/rooms.plx?gameid=7 (canasta)
I have a lot of fun while playing at gamecolony.com and training my skills. I highly recommend that site for all of my European readers.