The food court mainstays in the Merchandise Mart are names we've all heard before--Arby's, McDonald's, Quizno's--which makes this Chicago institution all the more appealing at lunch even if yes, it's fast food all the same. And this is why: Single, double- and triple-decker cheeseburgers stacked on a crispy bun. Customers pile on their own toppings, from tangy relish, pickles, onions both diced and ringed, along with ketchup, mustard and mayo. Plump, golden brown fries complete the meal. If red meat is out, the stand also serves grilled chicken and Monte Christo sandwiches.