Books have been written on the topic, one by the person who founded this website:
Mileage Pro
By Randy Petersen, Randy Petersen and Tim Winship, Tim Winship
(I think there is a more recent book, too.)
Randy also has
Inside Flyer magazine which has a monthly article rating a hotel or airline program.
Check out these elite of the elite programs:
United - United Global Services
Marriott - Platinum Plus
Starwood - Ambassador
Each is by invitation only with no public documentation on what is required for inclusion.