Conqueror of the Viridian Gym
Another thing I found out recently in GSC is that Oak has a line if you reach him in Pallet Town with no Kanto badges. I normally get the Kanto badges as I go round, but this time round I decided to leave them until the end to make it a true (piss easy) boss rush. Oak actually says "Have you not been collecting Kanto badges?" rather than his usual spiel. I assume it's the same in HGSS as well.