Smoky Mtn. Brewery. It's up behind Calhoun's in Gatlinburg, and there's one in Pigeon forge where the firefighter putt putt is. They have a limited menu. Their pizza is some of the best I've had. They have awesome burgers. But it's the beer that you seek, young man.
For Mexican, No Way Jose's used to be pretty good, but I haven't been there in about 10yrs. I suggest it because I've never seen it anywhere else, so it must not be a big chain restaurant.
J.T. Hannah's is really good grill type food, and has a cool atmosphere.
Tom & Earl's Back Alley Grill (Gatlinburg) used to have the best hamburger in town when it was a British Pub. I'm not sure if the menu changed, or just the name. It looks the same.
Flapjacks for breakfast is nice. A tad pricey, but not nearly as much as Pancake Pantry. I like their Mt. Leconte special. I'm curious to try Crockett's Breakfast Camp in Gatlinburg.
Go to the Apple Barn in Pigeon Forge, but do it at lunch time. Less of a crowd and it's less expensive. Every room you eat in is different, so ask the hostess what their favorite seats are. There are some in an old farm house style room, and some where you sit on a front porch swing as you eat.
People love Huck Finn's for their all you can eat vittles. To me it's just fried food.
The Island: I wasn't personally impressed with Timberwood Grill and Margaritaville was way too expensive for simple foods. Mello Mushroom just got bleh after a while. Much better choices out there.