It depends, among other things, in part on where you want to use points for hotel rooms.

For example, some chains only have big city locations. It doesn't matter how much you might like Hyatt, for example, it's SO big city oriented that there's not even a single one in Portland OR for example, let alone many decent-sized cities even smaller than that.

As another example, if you're interested in international awards, some chains have much better availability in some countries while other chains in others, and still others have availability only in the US.

So no one can say which one is the best for you until you narrow it down to the chains that would work for you (locaitonwise, etc) IF you could earn awards at a good rate and redeem them easily enough.