Here's an interesting one:
CashTC - Although they have not officially announced their launch yet, you can still sign up and start promotions.
Unfortunately there are no galleries at present, but I understand they will be arriving shortly after they've added a few more partner "brands". In the meantime, there are loads of glamour style content sets available to peruse and push. I sent them an email a short while ago about how affiliates might create some deep links to those content sets that will track the affiliate IDs, and will post their reply when I get it if you are at all interested.
Incidentally, it is not a monthly membership site, but a free to join/pay per download concept with 50% commissions paid through CCBill.