In which cards game 4 players participates?

I love playing poker, especially online poker. And though this is not strictly a 4-player card game, the thing is you can play whether there are just two or more players, which means more excitement and fun. But of course, if you just want 4 players, you can still do so and enjoy the game. I always play at www.playboypoker.com together with my friends, sometimes we also play for real money. :)