Depends on the week. Week one, I go to our Hawkeye Club bar and order a (frozen--we're in Florida, after all) tenderloin. And yes, I go Vincent Vega and threaten to shoot anyone on general principles for putting ketchup on their tenderloin sandwich.
For watching at home, September games usually go with grilled brats, homemade kraut, cheese and crackers, maybe some summer sausage. Beer, wine and whatever else gets poured in my glass are all fair game.
October/November games is when the chili gets made and consumed with gusto.