personally, I would prefer the thief/mage, if you are dual-class, otherwise, I would prefer the thief mage
http://www.gamebanshee.com/ubb/biggrin.gif. Because the Illusionist can't learn necromancer spells, which is REALLY annoying. And, a mage dualed to thief... forget it. It will never get the cool spells etc. etc. (except, ofcourse, that you dual-class him at level...20)