I've been doing pretty well with
Puffycash - they aren't saturated and conversions are pretty sweet - I always look thru review sites to see how a program converts and these sites rank very high on review sites:
PuffyCash.com
They have a lot of niches, shoot their own content and are very friendly people to deal with - I'd definitely say give them a shot. They use Nats for stats and so on - but ccbill is their billing.