Bulldozer Barb

HP: 30k minimum

Critical Hit Chance: 40 absolute minimum before Battle Rage, try and get at least 50

Critical Hit Damage: 350%

Armor: 5500, if lower you can use War Cry to make up for it.

All Resistance: Try and get a minimum of 550, but if you can't, use War Cry - Impunity to make up for it.

Lifesteal: As much as you can.

Amulet, Gloves, and Rings: Critical Hit Chance, Critical Hit Damage, and Strength. If you can, get Vitality and All Resistance as well. IAS will increase your tornado ticks, but isn't required. Hellfire Ring and Leoric's Signet if you're leveling.

Helm: Crit, Strength, Vitality, All Resistance, and socket. I prefer an Andariel's Visage myself, even though it lacks a few of these. Personal preference, like I said before, you don't really need IAS for this build.

Bracers: I love Lacuni's Prowlers for the +move speed, but could get any bracers with Critical Hit Chance and wear a Tyrael's Might chest instead.

Belt: Immortal King's Tribal Binding is likely the cheapest Mighty Belt you'll be able to find with the required stats. You need lifesteal, the higher the better, and the +maximum fury is always good. In addition, it can roll a mod that reduces the fury cost of Rend or increases the damage of Bash, which is always good.

Boots: I love Firewalkers because of the unique affix. The unique affix "Burns the ground you walk on", allows you to break through environmental breakables just by walking into them, saving you precious seconds every run. Try and get them with Strength, Vitality, and All Resistance.

Weapon: A Doom Hammer is ideal because of the way cooldown spells get their damage. Cooldown spells get the damage from your DPS multiplied by the unbuffed attacks per second of your weapon... but if the APS of your weapon is below 1, it becomes 1. So you get a little bit of a damage boost from using a Doom Hammer because it has a slightly higher damage range but a 0.9 attack speed. So if you had a Skorn and a Doom Hammer with the exact same stats, and the exact same listed average DPS, the Doom Hammer would do a bit more damage on cooldown spells.

Unfortunately, finding a Doom Hammer with good stats is difficult. If you can't find one, a Skorn will work. High critical hit damage, Strength, and a socket are required, with Lifesteal being perfectly ideal but unnecessary. 

Passives: 

Bloodthirst is very nice, because 3% lifesteal just isn't enough to keep me alive versus molten mobs. If you can get a weapon with lifesteal, you can always swap this out for another spell.

 

Weapons Master is good because it gives +10% Critical Hit Chance with Maces and Axes, and also the reason we're going with a Doom Hammer or Skorn.

Ruthless because... well, I don't think I even need to explain this one.

Mouse 1, the main fury generator: Bash - Pulverize is my preference due to the Pulverize shockwaves proccing Battle Rage - Into the Fray on any monsters hit behind the main target, but some people prefer Instigation for a guaranteed 12 fury per attack. Your choice.

Mouse 2, the Elite pack killer: Rend -  Ravage is what I'm currently using, but I've also played with Hammer of the Ancients - Smash or Thunderstrike. Rend is really good for enemies that love running, since it's constantly doing damage, while Hammer of the Ancients is good for hitting once or twice and killing them outright. HotA does benefit from IAS, so you might prefer it if you happen to have a good amount on your equipment. If you're having trouble staying alive, might want to switch your Rend rune to Blood Lust.

Keyboard 1, the secondary fury generator: If your resists are a bit low (like mine), War Cry - Impunity is very useful. Otherwise, you can either use Charge or swap it out completely for Leap, allowing you to jump over walls in Arreat Crater 2, Tower of the Damned, and a few other places, increasing the speed of your runs. If you choose Leap, Call of Arreat is a particularly good rune, allowing you to group up enemies before smashing through them with Furious Charge.

Keyboard 2, core: Battle Rage - Into the Fray is our main way of keeping Sprint up, giving fury off of most of our other skills.

Keyboard 3, core: Sprint - Run like the wind is one of the core skills in this build, killing trash mobs that survive Furious Charge.

Keyboard 4, core: Now here is the meat of the build, Furious Charge - Merciless Assault. This is our main skill for killing off trash mobs, and it does a pretty damn good job of generating fury as well. The Merciless Assault rune reduces the cooldown of the spell by 2 seconds for every enemy hit, allowing you to have an essentially 0 cooldown spell if you hit 5+ enemies, or 3+ enemies while under Empowered shrine buff.