Pretty much all the restaurants in Roppongi Hills are "best of breed" franchises and, for the quality, quite reasonably priced. I can personally recommend Wako Tonkatsu, which gives Tonki a good run for the money when it comes to tonkatsu, and Konaya, a curry udon specialist.
And of course sushi in Tsukiji early in the morning is an absolute must: both Sushidai and Yamato Sushi serve, IMHO, the very best sushi in the world.