I have played on a few over the years,PKR, Betfred,888, PartyPoker, FullTilt,, GGPoker, PokerKing, and of course Pokerstars, to be honest, I always return to Pokerstars, there is just something about their software, and I feel safe and secure playing with them.
The variety of games and the ease to find certain tourney's is amazing and can be affordable to any player from the 1 cent buy-ins to the skys the limit.
There are a few drawbacks when it comes to the Chest rewards as I know before I open a chest what the most likely prize it is going to be, but lets be honest they are in this business to make money not give it away, but all being said I don't play for the rewards, I play because I like to play Poker.
Making money at the game, I leave to the Professionals.
When the fun Stops, STOP!