We stayed in the Palm Springs area for a few weeks last winter and plan do spend a month or so there this winter too. We really enjoyed it. Lovely area with lots to do.
The Signature Resorts park in Indio is amazing. We stayed there for a few days. It was definitely on the pricey side though. But if the price doesn't concern you, I'd say it's "the" place to stay.
The majority of the time we were there, we stayed at Shadow Hills RV Resort
. It was a bit more moderately priced (about $50/night - $300/week) and even though it's not as fancy it was still quite nice.
A friend always stays at Happy Traveler RV Park
. We drove through there one day to check it out. It didn't look too bad if you don't have a big rig or really deep slides. I'd say 36' or less would be okay. Any bigger though and it would be just too darned tight for my comfort. Kind of a no frills park, but seemed clean and well maintained and I do believe it's the least expensive of the three I have mentioned. It's also fairly close to the Palm Springs downtown area so with no toad, could be a good choice.