Sacred Haven of Debauchery

Well, summoning turned out to be the best training for me, but leveling up gets tedious pretty quickly. One or two casts are enough for a medium-difficulty battle while I sit in stealth and munch on popcorn. Although, the most boring spells in summoning are precisely the master-level ones. Why would I run around with an atronach or a zombie when I have all sorts of skeletons from Cairn and dreadlords?