How about a category where you have to play the whole run on hard or expert mode? In normal mode you can basically just run through all the acts almost with any gear and basically use same skills the whole run. This would mauby allow for more tactical approach to the game and you couldn't pass the bosses with just standing next to it. In d2 normal difficulty is way more harder than in d3 so it works fine there, but in d3 normal difficulty is just too easy and it wont really challange players enough.