I though I was everyone's favorite SC...
In-game, though, I like cyclopses and Bune. Of the ice devils, only he (without empowerment) can self-cast luck, body ethereal, astral shield, and astral weapon. And he's only marginally weaker, stat-wise. Those 4 boosts allow you to kit him out with a full set of equipment ignoring ethereality, luck, weapon damage/armor piercing ability, charcoal/vine/eye shields, making him the best in my view.
Edit. As noted below, I mean Bifrons. As for Mind Duel, I've never encountered it in a game...