Hydra's not bad at all, made about 16k with them last year -- always timely payments and awesome service from their reps (had ellie at the time.)
i have a freebie site and i was considering them, but it seems like their "free sample" offers are kind of spammy. They are the ones where you need to refer users for a free sample, but then they have to do an offer and a survey as well. I don't want to piss off my blog readers with bunk freebie offers. Anyone use these?