WorldWinner

http://www.worldwinner.com/
Join Worldwinner.com and compete in card games, arcade games, strategy games, word games and sports games for a change to win cash prizes. Players receive competition scores based on how well they play each game and the player with the highest score wins.

Gamesville

http://www.gamesville.com/
Play free online games, inluding bingo & casino games, card games, puzzles and word games, for a chance to win cash and other prizes. Participate in cash competitions with other members for a chance to win more money. Any registered member (18 or older) from anywhere around the world is eligible to receive prizes.