Get ready for
Why locals love it
Berlin has an internal burger ranking, and depending on which list you look, BBI is currently in the lead. Not surprisingly so: The burgers are massive, stuffed in a highly creative way and made by hand and with love. Prepare for feta cheese, hidden spice, anything but iceberg lettuce and for getting yourself really messy. There's lots of napkins.
Why you should visit it
To be surprised by the size of the, uhm, restaurant, and its capacity to nevertheless cater so many hungry mouths. Also, please be very hungry when you go there and intend to order a burger PLUS fries - well, any option from a wide range of fries.
Try take-away - the canal is only half as far if there is a huge crowd. Or just sit on the sidewalk, but please mind the cyclists!