Strenght of course, for the melee damages. Then Skull Crusher for the bonus when hitting the head. Sex T. and cardio (agility) for the stamina. If you choose the club : flurry of blows. Sledge hammer ? Heavy Metal. Machette ? Deep Cuts. Stay down ! can wait but is usefull too.In parallel but less urgent, pain tolerance & light or heavy armor.
And imods for your favorite weapon, they are unavoidable.
