My dad is a member of Marriott, and seems pretty satisfied with them. I think, but I'm not positive, he may also be a member of Hilton Honors, but I don't think he stays at their hotels often. More often than not, I think he stays at Marriott Brand hotels (Courtyard, Residence Inn, etc.)
I'm a member of Choice Privileges (they own Comfort Inn, Clarion, Quality Inn, etc.). I actually don't travel that much, so don't get a chance to rack up enough points for a free night. I haven't had many, if any, bad experiences at their hotels. Only complaint maybe was one hotel was next to a freight rail line (not their fault), so it could be kind of noisy at night, but I'm a pretty heavy sleeper, so it didn't really bother me.
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)