Demon Hunter and Wizard for me all the way. I haven't found Ray of Frost particularly interesting at all, I hope the later runewords improve it substantially. I was upset when they moved Disintegrate up to a higher Clvl because that skill is extremely fun, palate swap or not.
With the wizard in the beta, I loved getting surrounded by as many enemies as possible, hitting Frost Nova (with the runeword) and then Wave of Force immediately after. That is a potent combo.