Best big rig RV parks you have found?

We are open as to gravel or paved. We prefer that the parking spot not be grass, but will consider grass/ dirt/ sand. We have enjoyed parks without activities, especially in areas with great nature around. We are currently wintering in AZ in 55+ parks with lots of activities and love that, too. We prefer parks where we can reserve a site, or at least a type of site with hookups & long enough for us. We are not comfortable with winging it... This usually puts us happily in close quarters with our neighbors and close to tourist attractions or natural beauty. Examples would be Grizzly RV park in West Yellowstone or El Portal in Moab. We have a fifth wheel that will soon be 10 years old. Thanks for your suggestions!