Bare with every other job mastered.

Seriously though, Sorcerer/Sword Mage. It's not a practical class for standard traveling, but vs. boss characters it's phenomenal. It's also a nice changeup from standard spell-casting.

I also want to give a nod to the normally worthless Bard job for actually being useful from time to time in this game...or at least the song ability. Requiem and the healing song came in handy often in my game.