For Service my hometown dealership, Payne Chevrolet in Springfield, TN has a great service dept. Rick Green, is a knowlegable and caring service manager(? not sure of his title exactly). We have had several Chevys & GMC's serviced there over the years & never had a problem. They have done a few warranty things on my Camaro & I have been very pleased.
They also have a great body shop. They order most of their Camaro stripeless & paint them on themselves. A friend of mine wanted stripes on hers the exact color of her husband's motorcycle. They mixed & remixed the color for her several times until she was satisfied & it turned out great.