I can only speak for what I've tried. I did briefly run
Getanaffair and it did well for me
And of course there's
Datinggold and the newest affair sites they have. You can ask them to fire your own pixel, and if your traffic is good you could probably get them to give you a pay bump for single opt-ins that would be better than what a network would offer. And you run directly with them so none of the cash flow bullshit that's been happening lately at some/many networks
No ppl single opts, but
Xpress/EroticAffairs are good. Haven't had enough money to play around with them more but what little traffic I sent converted very good. I'd say on par or almost as good as DG. Can also fire your pixel with them which for me is a big deal. Nice fat PPS and % payouts.