In & Out. Fresh never frozen beef which they mince and distribute themselves having received cuts from select suppliers (hence though they started in the same year as McDonalds and in California, and along with the fact that they don't franchise, they could never expand as fast).
Pros: Fresh beef, highly customizable, cheap.
Five Guys. Uses same beef as any other chain that uses frozen patties. But it is the endless toppings and varieties of toppings that makes me go there once in a while. When they get the bacon, mushrooms, bell peppers, various sauces in the right combination, it's a great burger.
Pros: Variety and quantity of toppings for no extra charge
Cons: Frozen beef (questionable quality), price (although toppings somewhat make up for that)