Over the past 3 years, I have stayed at all of these at < $350/night (except for Mayakoba). I'd stay at all of these again (and hope to soon)/

Mexico

• Four Seasons Mexico City. Fantastic hotel and our trip overlapped with fashion week, which we were able to watch an event from our window with our upgraded room to top floor in the interior courtyard.
• Rosewood Puebla - this hotel is no longer a Rosewood (and not sure if it is still in FHR?), but we had booked it for <$190/night. We were upgraded to a suite.
• Banyan Tree Mayakoba - we were upgraded to a larger suite with a large living room, this was about $435/night - which now is $1,000+/night

United States

• London west Hollywood - this is one of the nicest hotels we've ever stayed and the largest hotel bathroom we've ever had
• Encore x2 - both times booked cheapest room and received upgrades to Panoramic Rooms at Encore. We did enjoy the free breakfast everyday and my wife enjoyed the spa treatment credit
• Mandarin Oriental Las Vegas - now the Waldorf, we had stayed just before the transition to Waldorf. We were upgraded about 20+ floors and upgraded from non-strip to strip view.
• Seattle Fairmont - classic hotel. We had to ask to move our room due to elevator noise and we ended up with a top floor corner suite that hadn't been renovated, but was still very cool.

Spain

• Gran Hotel Malaga - great hotel - we were upgraded to a quiet interior courtyard view. The room was probably the best value for the luxury we had ever saved