I'm playing a Necromancer right now - he doesn't have to do much of anything but stand back and sip tea while his minions work over the bad guys. My Barbarian did give me finger stress, though. Spellcasters are more fun to play.
I've beat the Dog with a spearazon, a claw assassin, and an axe barbarian. I'm chicken to try spell characters, 'cause those things DIE lots in early levels.
Sorceress all the way, Glacial Spike is perfect for crowd control. The only problem was when I did multiplayer with a Necromancer, who got annoyed that I kept shattering the monsters so he couldn't reanimate them.