tyrael hands down.
What little I have played so far, I have enjoyed the Witch Doctor and all of his creatures he can spawn.
I still love my Monk, but I'm thinking about switching to a Crusader when RoS is released.
Even though my main's a wizard, I think favorite's a demon hunter. It's hard to choose, though. For NPCs, though, I really like Shen and Lyndon.
got to be demon hunter all the way.
The female barbarian! :D(The Scoundrel is a close second).
I'd have to go Demon Hunter. If you're talking about NPC's, then I have to say Deckard Cain.
Wizard, nice burst damage :)
Sorcerer is the best.
I assume you mean any character, so Zoltun Kulle, dedicated, insane and pro-humanity.If you mean player character, the Wizard then, especially with the Frozen Orb spec being back on the menu.
Dat Monk tho!
Wizard all the way!