And what is your stay pattern? If you can only qualify for one, my suggestions are:

If you value suite upgrades above all else, you want Starwood.

If you want the most consistent product and the concierge floor treatment most every time, you want Marriott. Also, it you want travel to smaller two and two.five star hotel markets to count towards renewals, Marriott is your chain.

If you want to earn travel awards, at least as long as they continue Frequent Free Nights, then you want Hyatt. Also in my opinion a good possibility of a more upscale property in metro areas, but a risk of a tired property in less premium locations.