Rao's
This classic red sauce joint in East Harlem is probably the least flashy restaurant on this list, but it's most definitely the hardest to get a table at. Reservations have been booked-out for the past 40 years, thanks to Rao's exclusive time-share system, wherein regulars "own" tables and can "rent" them out to friends and family, or even to a charity auction (you'd be surprised how much the coveted family-style Italian meal at the place can be worth). If you ever hope to eat here, you better start making friends in high places - or hope someone dies.
Rao's, 455 E 114th St.
[Photo via @jgreeny6]