I used to be a huge proponent of Marriot Rewards but last year I decided to make a change and try out Priority Club hotels http://www.priorityclub.com.
The availability of hotels from this group is just as good as Marriot, at least in the cities that I am visiting.
Here is a tip if you are going to be staying at these hotels.
Register yourself as a Priority Club member. It costs nothing so you have nothing to lose. Go to the priorityclub.com website, go to the word offers, and you will get a drop down menu. The last item on this menu is my offer status- click on this. It will ask you to login if you are not already.
The next page will be a list of offers you qualify for- typically by staying some number of nights you will get X thousand additional points.
Here is the tip: Sign up for all of the offers. Then forget about it. And try to stay at Priority Club hotels.
I wouldn’t change any of my travel patterns to get extra hotel points but this way you are covered if you do happen to stay.