Im using this build to beat Act 2 . http://us.battle.net/d3/en/calculator/barbarian#WSRVkP!bZU!bZZccc
what I do is use zerker , furious charge .. the cool down on furious charge is lowered by about 6 secs for hitting 3 targets . Also I gain 15 rage for using it combined with warcry etc which keeps zerker up longer .
The stats from zerker overcome alot of gear issues , and the 50% crit bonus damage rune + 99% crit bonus from weapon + 38% from gloves .
Not sure what else adds crit but my crit is rated at 230% bonus damage .
I then stacked alot of str and vitality . I actually lowered my resists quite alot so Im a bit of a glass cannon when not buffed .
Damage is around 25k . When I crit I do around 86k damage.
edit : once I get a decent 2h axe or mace I will swap relentless for weapon master .
with zerker up I will then have 30% chance to crit .
with charge doing 195% weapon damage I should beable to land close to 150k hits .
Since tanking Act 2 is pretty futile unless you out gear the zone I feel that killing the mobs in as quick fashion as possible is the secret to farming this place .
Also remember ignore pain lasts 7 seconds so you want to dispatch of the mobs within that time which means you need more dps not more resists .
Str > Vit > Resist > +Armor > Physical Resist
Also the beauty is I can charge through a pack of creatures and I reset the CD to 0 and charge back through them again and again until they are dead without even taking a single hit .