(if you have any suggestions for additional links let me know)
Webmillion - 10 free chances a day to win $10 million. If you sign up using this link, I'll get something when you win!
FreeLotto - 4 free chances a day to win $10,000, a car, $1 million or $10 million. It can't hurt to try, right?
Uproar - fun multiplayer games like Puzzle-A-Go-Go (it's like Wheel of Fortune).
Riddler - single player and multiplayer games!
Gamesville - Bingo and other games.
DuJour - Daily riddles/trivia/vocabulary games. Win prizes.
Treeloot - Click on the right spot on the tree and win prizes.
Prizes.com - Free instant win prizes.
Prize Central - Win tokens for prizes playing slots, blackjack, roulette and more.
Win Dough - A little floating pop-up window that shows ads, but occasionally has a banner that if clicked on will get you prizes.