One of the great remaining strictly regional foods in America is Cincinnati Chili. Created by Greek immigrants in the early 1900s, it has no relation to Tex-Mex chili.
It's served over spaghetti, with grated cheddar on top, and in between -- optionally -- are red beans and onions.
My favorite place to have it is Skyline Chili, a chain of diner style restaurants. I had one night in Cincy this week and enjoyed a dish of 5-way for the first time in years.
If you'd like to try it at home, I know there are recipes on the net, but the one I've made with great results was by Jane and Michael Stern in their wonderful book, Square Meals.