If you're on a per diem basis, I'd say stay in the cheapest hotel that good for you. Points don't compare when you're pocketing $65+ a night. However, if you're not on a per diem basis, but rather on a stay anywhere deal as long as it's under a certain amount than I would say Marriott, Hyatt, Priority, Starwood and finally Hilton in that order. I’m on the stay anywhere as long as it’s under a set rate and our limits are pretty high. Our NYC rate is $224, Atlanta is $132, Los Angeles is $123 and DC is $157. So, there’s slightly more flexibility with our tour.
I feel that Marriott/Hyatt has the best program hands down in the industry today. I would say that MR is slightly better than Hyatt due to the shear number of hotels that are in their portfolio. Priority isn't bad, but their points are slightly inflated. Yes, you can use their points for other hotel chains, flights and etc., but if you calculate the cost per point, it's way too much. Hilton are the worse, they're point system are even more inflated than Priority. I have stayed at only 3 Hilton properties since I started traveling.
Hilton's top category 7 requires 50k points vs Marriott's top Category 8 at 40k. In addition, 95% of Marriott hotels top off at category 6/7 (30k/35k) and that includes most JW Marriott. The categories 8 are those really upscale ones in London, NYC and Paris. Marriott, also have a feature where they'll give you 120k airlines miles (most American base carriers) PLUS 7 nights stay at a category 6 for 300k points. You can't beat that at all. Categories 6 are essentially 90% of the JW Marriott portfolio hotels. If you want a lower tier hotel, you can use fewer points. For about 300k, you got your vacation paid for and that's with a business class seat to Asia (low) or Europe (high) depending on airlines. You can't get that with any other hotel chains.
I like Hyatt for their level of service, whenever, I travel abroad (I been to 85 countries & 15 this year) my first hotel chain I look for are Hyatt hotels and if there isn't one I'll go for JW Marriott. With Hyatt I get guarantee suite upgrades for the lowest price rooms. Example, I stayed at the Grand Hyatt Cairo earlier this year and got the Diplomatic suites with 2 balconies over looking the Nile for $90/night. Most recently at the Grand Hyatt Istanbul, we got the suite with full kitchen and butler service for $150/night. Marriott would never upgrade to those rooms. However, with the JW Marriott Internationally, I always had exception level of service that even the American JW Marriott can’t compare.
As for priority, I haven’t stayed at any Priority Club hotels, except several Intercontinental hotels abroad and domestically. I always get 8am check in and upgraded to their Intercontinental Club room and if that’s not available to the next suites. If I show up at 8am and there isn’t a room available, they’ll house me a in room until a suite is available. So far with IC, I have been upgraded to a suite 100%, without asking. The best part is that the mini bar is free!
I am basing this on my personal experiences.