Ichiran ramen - The go to ramen in Japan. Super rich tonkotsu soup base with hakata noodles (thin noodles)
Rokurinsha - not really a ramen, tsukemen to be exact. Best for people who like rich taste. Very conveniently located at Tokyo station
Muteppo ramen - not your usual ramen. Think noodles with even thicker soup base. It is like gravy, very unique taste for people who wants something different