Fighter/mage rocks. Unstoppable, unkillable, cheesy and yellow from level 1/1 till the end.
Generic archer-->mage is also cheesy. (Provided you have tactics mode).
They are fun (apart from being yellow), and
very strong.
After certain level any "spell casting solo" is easy. Time stop+ GWW =dead enemy. And sorcerer is a walking arsenal of destruction when he can cast 9 level spells. Just refer to Dundee's spell pick list, and gg.