The Singer or War Cry Barbarian is an extremely fun and effective build, using the War Cry skill for not only stunning enemies but also damaging and killing them. While decently mana intensive, this build is actually extremely safe as it often includes many points in Battle Cry and Battle Orders as well.
Video Build Guide
War Cry’s Strength is in its long stun in area-of-effect format. While you’re casting War Cry, all regular monsters are stun locked until you kill them.
The Singer Barbarian is more of a support build than it is anything else, but it is viable enough to solo through Hell.