3. R.F. O’Sullivan & Son
Like your burgers super-sized? With dozens of different burgers on the menu—from the kickin’ Jalapeno Burger to the flavor-packed Black & Blue—O’Sullivan’s sandwiches aren’t exactly “fast food.” The half-pound patties are so large (they’re almost round when they hit the grill) that they require patience as they cook. So belly up to the bar in the middle or grab one of the tables circling the bar as you wait. As an added bonus, large, hand-cut fries arrive with your hamburger. — Jesse Nunes
282 Beacon St., Somerville. 617-492-7773. rf-osullivan.com. $8.25-$9.25.