This is kind of out of the way for the true DFW crowd, but if you live in the Sherman/Denison area or travel up that way once in a while, try...The Old Mining Camp
3003 Woodlawn Blvd
Denison, TX 75020, US
It is the best BBQ I've had - I recommend the pulled pork sandwich, brisket sandwich, any of their burgers, and the baked potato with brisket is delicious with plenty for two meals.
The only disadvantage is that it's all outdoor seating so you'll need to order it to-go or eat in your car during the cold winter months unless you like having frostbite. Still, on more than one occasion I've found the food worth sitting outside in the cold to eat.