My first choice is a local ramen soup shop. There are ramen shops littered all over Tokyo, but this one is something different and is always great. Most ramen in Tokyo is pork ramen soup, but this one’s specialty is fish soup, called Niboshi soup. Unique and really special.
Next is a pork ramen soup shop, and this is about as basic and cheap as can be found. Cheap and basic, but just purely great, original Tokyo ramen soup. Hands down excellent.