Coolest fantasy format you've played???
Other than the usual, the best and toughest format I've played is a favorite franchise format. In this type of league, you can only have players that have played one game for the franchise that you've picked. It definitely adds a tough and new twist to the league.
It also gives you a chance to play only the players from your favorite team.
I've only tried it in baseball but it should work well in basketball. I've created a private league at nba.com called Favorite Franchise League-serious ps nba and the password is nba.
Just wondering what other formats you play besides the usual?
Everyone is welcome to join the favorite franchise league, it's challenging and a funner way to play I think.