I have had luck at Perkins and Applebees. I know that many would say not to eat at these places but I have educated the two that I go two and they will actually clean the area of the grill before cooking on it now and the Fiesta Lime chicken is otherwise gluten free and the pork chops with salt and pepper is OK at Perkins (if you can get them to clean the grill).
I have also liked going to Chipotle. Papa Murphy's gluten free pizza at my location is safe as they use a separate station to make the pizza, though you are limited to veggies and pepperoni.
Not a restaurant, but Burning Brothers Brewery is 100% gluten free. You go to their brewery/taproom they don't let gluten of any source into their facility. You can sit down and have a beer, cupcake, chips...ect and it's all great and gluten-free. Plus the owner of the brewery has celiac disease so he knows what gluten-free for celiacs is.