Flagstaff,AZ.; St. George and Cedar City,UT.
Not so much to choose from in your UT stops.
Painted Pony in St. George will be the finest dining option. I've not been, but it gets good reviews. If you've never been to a ChuckARama it might be worth a visit. Uniquely Utah, and a better than average buffet offering.
Cedar has even less to offer, but there is hope. I am a fan of Sullivan's coffee shop (adjacent to their steak place). Food is solid, service as well, and there's a nice salad bar available. For a really good green chile cheeseburger head for Top Spot, a funky little drive-in place.
Flagstaff has Cottage Place for fine dining. The price range is high for Flagstaff but the prices are low compared to PHX and Vegas. The food and service is stellor.
Brix in Flag is also very good. The menu is a bit more creative than Cottage, but the food is not as well-executed and the service is sporadic.