I've settled on South St Burger being the best burger meal (well at least the best fast food burger as Richmond Station's burger is pretty amazing) downtown. The patty is always fresh off the grill with interesting toppings like cajun onions and guacamole or premium toppings like pineapple or brie. I like to see them put on the toppings as compared to Hero burger where it's all assembled in the back out of sight.
Perhaps the best part is the fries, courtesy of New York Fries. They usually finish the burger first and then finish the fries last, so they always come out hot and fresh from the fryer. I don't think they keep fries in their fry bin like those fast food joints, they just have single portions ready to hit the fryer so they always come out hot, which is how you want it when you freshly grind some sea salt on top or add some cajun spices.
It's also outside the path, which keeps the line-ups short and there always seems to be more than enough available seating.