The Ritz Carlton is definitely one of the nicest hotels in the greater Palm Springs area.  It's expensive, but the experience of being up on a mountain is pretty unique.

If you are looking for a unique couples experience the Sparrows lodge is a great option

A new property the Drift offers something different, larger units many with kitchenettes.  It's more of a home away from home and very centrally located

A great central location with a rooftop pool, the Rowan is new and it's worth a visit

If you are looking to stay in the upscale shopping district of El Paseo, the Hotel Paseo offers a perfect and very walkable location.