Ground is pretty hard- basically it's groudon or shit (it's tragic that groudon at level 22.5 already out DPS's a Level 40 maxed rhydon). So either you burn RC into 6 maxed groudon or deal with the poster child of the poverty gap that is Rhydon.
Water is pretty hard as well analogously, but gyarados is at least still vaguely competitive compared to rhydon...