In-N-Out

In-N-Out's Double-Double burger comes in at second place just behind Shack Shack for me when it comes to best "fast food" burger. (Then, Whopper, Five Guys, Big Mac for those wondering.) I like going classic when I'm there, but there is a not-so-secret secret way to order off-menu and really indulge your fatty cheeseburger fantasies.