What is your favorite frequent flyer program? Mine is United Airlines. I don't live near a United hub, but their partnership with Star Alliance and the benefits really motivate my desire to fly them whenever possible.
Preferred Frequent Flyer Program
American Airlines AAdvantage. Not because AA is the best, but because we are captive to one of their hubs.
I am on the United bandwagon as well. Their United Explorer card and the mileage accrual really makes it worthwhile to make them our primary carrier when feasible. Plus the reward redemption on United is pretty good.