the secret to burger spot quality is a mix of different cuts. like chuck + a little ribeye or something, ground up in an actual meat grinder. then you need a really hot flat grill. that's all it is. the fat from the chuck and all that melts and crusts the burger against the flat grill, and thats the magic secret right there. i have four diff friends that worked for zippys giant burgers in west seattle and that was a pretty popular spot... its just about the grind and the grill
certain seasonings and stuff can really set a burger off but with some high quality fresh cuts with good beef, all you really need is some salt and pepper