Bring cash, roll up your sleeves.
There is a reason they are number one on this site...they are that good. You don't have a lot of options, 1/2 lb or 1/3 lb, cheese or no cheese, but you won't mind. Besides, other places try to make the burgers too fancy. Come before you get too hungry or at an off hour or you may have to wait and lurk to get a seat, but don't be tempted to go elsewhere, the wait is worth it. They have a nice selection of tap beers, but make sure you bring cash because they are old school and just recently got a cash register. Order a burger, roll up your sleeves so you are not tempted to use them as a napkin while eating the delicious burger.