Rhode Island Olyneyville System Weiners. They're like a small hot dog but made of pork covered in a home made secret hamburg meat sauce, mustard, celery salt and onions. They're only made in RI.
Spike's Junk Yard Dogs...This is a small chain in RI that has amazing all beef dogs on fresh baked rolls and a ton of topping combinations to choose from.
Wings To Go...small local chain with great buffalo wings and fingers. They also have other sauce combinations.
Boston Area Kelley's Roast Beef
New Haven, CT Frank Pepe's Pizza
DC Area I completely agree with Five Guys Burgers and also California Tortilla.
Los Angeles I can't believe no one has mentioned Roscoe's Chicken and Waffles. Their fried chicken is amazing!!!
Houston Area Papa's BBQ