Not to nitpick too much, but Illinois and Missouri are not in the South. The are solidly Midwest.
I think the best "foodie" city in the south is New Orleans, no contest. Quality as well as variety. There are also regional choices in the deep south that you don't find in other parts of the country - crawfish and alligator come to mind (Louisiana and Mississippi in particular).
Carolina is solid barbecue country - smoked meats with a wide variety of sauces. Pulled pork and ribs are most common and delicious, but a good brisket is heaven on a plate.