Obviously not free, but otherwise a great coin is Wagerr, offering decentralised betting on the block chain. They have been live for a just over a month now and have already a decent volume of bets ($1m+). They offer mostly sports betting (MLB, NBA, NHL, premier league, etc) using a very easy to use wallet. Odds are good and betting fees are low. And they're in the process of setting up a fiat gateway, building a new HTML5 website and currently applying for a licence in Malta. Very promising altogether, loads of potential and yet another real life use for the blockchain!

Have a look!