Hey Tom:
FlashCash kicks ass, the member retention rocks.
It has 2 Asian sites, 1 Cumshot site, 1 Bizarre (peeing) site, and various others.
FantasymanMoney (Cybererotica)
Too many damned niches to list
InsiteAdult Quite a few of those niches again
MoneyTree Various niches.
Those should cover all your bases