Just to add another wrinkle...

If you switch your Hilton earnings from points+points to points+miles, you get 500 miles per stay. These can be put in your AA account (and others), which can then convert back to HH points at the rate of 5000 miles -> 10,000 HH points.

Obviously, whether or not you use this option depends on your rate and the property you stay at, but the option can be changed at will.

Using this technique, I was getting almost 30 points/$ for a while earlier this year.