Holly K.
Yelp
Solid burger chain, situated in the heart of Seaport (right on Seaport Blvd). I order dinner from here frequently (to-go), and find it very convenient that you can pick up your order from the outside walk-up window. Service can be slow at times, and if you find yourself waiting for an order longer than expected, ask about it. Chances are they forgot to (or just didn't) call your name, and immediately just placed your bag inside (instead of outside).
The burgers are delicious, the meat is juicy, not greasy, and good quality overall. They offer several different pre-made burgers, or you can make your own. Various toppings available, such as Shake Shack sauce and seasonal white truffle aioli, cherry peppers, bacon, mushrooms, and more. In addition to beef patties, they also offer a vegetarian burger (fried mushroom).
Crinkle cut fries are crispy and golden brown on the outside, and soft on the inside, again with the option to have cheese, bacon, or any of the available sauces on top. Shakes and custards are also tasty- vanilla, chocolate, strawberry and cookies and cream; non-dairy options are available. Shake Shack also offers hot dogs, grilled cheeses, chicken sandwiches, and chicken "bites". I have not tried any of them though. Restaurant itself is a little overpriced, but still one of the cheaper restaurants you'll find in Boston.
Note: VERY busy location, at all times of the day. I find it much easier to do pick-up or delivery, then attempt to find a seat, or have to deal with slow service.