i use Frostner or 2h hammer vs bonemass. silver sword\blackmetal sword vs yagluth, draugr's bow vs moder(not melee though).

so i'd say most op melee is probably a sword (fast enough attack, good damage and you can pair it with shield). 2nd place is frostner(especially vs bonemass\yagluth) and 3rd is crystal battle axe(you can level axes easily while chopping wood, so it's a good fit)