I've heard good things about companies that have a "skenzo" feed, but I haven't managed to get a foot in the door at any of them. Over the last year most of them (if not all) have dried up and dissapeared. I've also heard sedo pro is good, but again I don't have enough "juice" to get an account.
From my testing of the companies I could get an account at, DDC and Parked are neck and neck for the highest payout. I lean twards parked only because they make payments through paypal twice a month. DDC is a paper check at net 45. You have to have a premium name to get a ddc account. If its not .com and getting 50+ typeins a day I wouldn't waste their time applying for an account.