I've spent far too much time trying to figure out the best yields on points programs, and after failing to use airline points, I've become disenchanted with them. There are no guarantees with these programs and the surest way to earn rewards is to stick to credit cards with a cash back program (while making sure to balance higher percentages back against higher annual fees), and spend at stores that offer points in a program like mypoints to redeem for gift cards, but in all likelihood, you'd be best just searching for the lowest price than hunting for points.
Just remember that airline points programs give you the best cash value for points when spending on flights (subject to availablity), hotel programs give you the best yield on redeeming for hotel stays, and programs that aren't brand based need to make their money somewhere.
Good Luck
