I am so biased that I have only tried a cleric and warrior. They weren't anything I enjoyed. The Rogue by far is the best class for me. I am not sure what a mage can do as far as damage output. I had a thread going a while back about biggest hits dealt, but no one posted any screen shots that I saw. As a lvl 25 Rogue on hard I avg Assassinate Stabs in the mid to high 400's and topped out at the low 500's. I have also killed a Red Dragon in Icemist Under levels with a flurry of seconds which culminated in hits of 398, 402 and 48. Yes, a double Assassinate Stab crit. And I have nearly the AC of HP of a Warrior with any resists that I might need. So, yes I challenge the thought that a mage is generally the best class.