Fred,
Are you waiting for someone to mention Kellers Drive In?
They're good. Good hamburgers on onion/poppyseed buns, fries, and cold beer. Good Chili/Cheese fries. And ugly car hops. What else is needed?
But if you come downtown Dallas. Tootsies is the best. They make homemade buns. Lots of meat. And a condiment bar to die for.