Rebatewager has cash back on loses which is good
Intertops from time to time has some good deals
BoDog once in a while
Although I browse around all these books in Europe, Asia and Australia and all they do is have incentives for players to re up
free bets, bonuses all the time, etc
Some books give you money back if your bet loses by a certain amount
Aussie books refund money on some tennis tourneys if your player loses in 1st two rounds
They have great marketing teams