I play as a rogue assassin on nightmare difficulty. At first it's a challange, but once you learn the moves and level up its a joke. Amazing game, but I'm not even halfway through the story and I've completed nearly all side quests, closed all rifts in available areas and I've killed all dragons. It's extremely fun and addicting, but got easy for me lol. If you want an easy class go with a mage and become knight enchanter when you can. There's a moveset that allows you to spam the same move over and over, get shield back constantly and you never have to worry about losing hp. I have yet to try a melee build, but those are two fun choices IMO.