After level 60, use the best Stormsheild you can find and the best weapon you can find that has Life on Hit.
Get huge armors with Strength, Vitality, All Resistance, and +Armor. Justice Lantern rings (+block) are OK, but a good rare ring with Str/Vit/AR/Life on Hit is probably preferred (for cost/benefit and for other stats that help dps, crit, etc). You want to get damage down so low that the 4700 damage or so that the shield blocks is 100% of the damage taken after mitigation... so each block means you take 0 damage. Same with Helm of Command vs Mempo.
The best build would be a team build with Rend... the best of both worlds. http://us.battle.net/d3/en/calculator/barbarian#acRkUP!bYc!YZYccZ
The weapon would be Axe/Mace/Mighty Weapon to go along with the Weapons Master passive, so you can get more fury via Into the Fray, to provide constant Sprint to the group as well as Rending every mob to make group kills much faster / give yourself lots of life regen via Bloodlust rune.
Heck, I think my next female barb will be this build.