I like Full Tilt poker alot, but it seems to force the action at times. UltimateBet.net is another good one. PokerStars and AbsolutePoker seem very similar to each other and are also good for a more realistic style Poker. Full Tilt is my favorite though, lots of people play there and there are always lots games to join and regular tournaments. I don't play for real money though i only offer opinions on the play chip aspects of the sites.