I would like to share with you the build I used on my Barbarian from level 30 all the way to 60. Why 30? Because that's about the point where you step into Nightmare difficulty. Act 2 especially can be tough. Normal mode is very easy but Nightmare ramps it up a notch and very often it requires a re-shuffling of your skills in order to progress. I was ready to give up on my Barbarian at this point because I was taking too much damage with my previous hodge-podge build. The fact that I was using a 2-hander didn't help either.
I came upon an interesting build on a forum somewhere but unfortunately I can't remember where, to link to it. I decided to give this build a try and I was very impressed. My Barbarian became an unstoppable force (and immovable object) and he sailed easily all the way to Inferno Act 1 using this build.
You won't have all the sweet runes that finalize this build from level 30. But the skills themselves don't change at all. Only one passive skill changes, but much later. Instead, the basic build continues to improve as you go along and unlock better runes. Furthermore, it so happens that you don't even need to enable Elective Mode if you use the same skill placement I use.
I found that this build works best with sword-and-board, i.e. 1H weapon and shield. Your mileage may vary with a different weapon setup but personally I wouldn't want to give up the extra protection afforded by the shield.
Without further ado, here's the build at level 30:
Frenzy with Triumph - This is your bread and butter Fury generator. It deals massive damage to a single target and it works best with a fast weapon. Triumph heals you for a significant amount when you kill an enemy. I consider it essential for survival. You will use this rune all the way to 59.
Seismic Slam with Shattered Ground - Seismic Slam is your main Fury spender. I love it because it deals massive damage in a 45 degree arc in front of you to all the monsters caught in it. More importantly, it knocks them back, allowing you to recover if you are surrounded. The rune simply improves the range of the skill and the knockback effect. This rune is so good that there is no reason to change it even at 60.
Ignore Pain with Bravado - It seems that Ignore Pain has become a must for most builds and this one is no exception. Pop it up whenever things become hairy. The Bravado rune is temporary until you can get a better one but it is still very good, knocking enemies back if they surround you and also dealing 50% weapon damage to them. In fact this rune can be used as an extra source of DPS if you so desire, popping Ignore Pain whenever it's off cooldown. While the cooldown itself is fairly short, I prefer to use it only when shit happens.
Revenge with Vengeance is Mine - Revenge is one of my favorite skills. It has a chance to activate when you are taking damage. So the more you are hit, the higher the chance. It procs very often when you are surrounded or standing in a pool of nasty damaging stuff. You need to keep an eye out for it but it does some nice AoE damage when you hit it. Make sure not to wait too long because the effect eventually expires. Damage aside, the main strength of this skill is that it heals you for a very nice amount for each enemy affected by the skill. It is literally a lifesaver. The rune (temporary until much later) increases the healing effect and also gives you some Fury.
Warcry - This one buffs your armor (and your allies') by 20% for 1 minute. The cool thing is that it also generates Fury so I use it whenever it is off cooldown, every 30 seconds. At level 30 there is no rune for it yet.
Wrath of the Berserker - This one is optional but highly recommended. It provides massive burst damage and even though the cooldown is long at 2 minutes, I like to save it for boss packs when I can pop it and destroy them in a few seconds. Runed, this skill becomes even better, but at level 30 you will have to contend with the naked skill.
Nerves of Steel - Awesome defensive passive. It increases your armor by the same amount as your Vitality. Since you will have a ton of Vitality anyway, this means that you will have huge amounts of armor. This passive does a lot to help mitigate a great deal of physical damage.
Tough as Nails - Further increases your armor by an additional 25% but also improves your Thorns damage. If you have a build centered around Thorns, this passive is a must. Otherwise it still does a lot of mitigation which makes it important for this build.
Superstition - While the previous two passives take care of physical damage, this one reduces non-physical damage by 20% and also gives you a little Fury when taking ranged or elemental damage. In all, it's a solid defensive skill and highly recommended.
As you can see, this build centers mainly around defensive skills but also has some nice health recovery via Revenge and the Frenzy rune, as well as good damage thanks to Frenzy, Revenge (again) and Wrath of the Berserker. Between all the mitigation and health recovery you will use very few health potions. For this to work you will obviously need a good 1H weapon and shield but fortunately these are cheap to buy on the Auction House until level 55 or so. For the shield I recommend as much block as you can find (ideally about 20% or so), and then armor. Shields also have Strength, Vitality (which also gives armor via the passive) and other desirable stats.
Progression from 30 to 60
This build will evolve in your journey to level 60 but the beauty of it is that you'll be using the exact same skills. Only the runes change, for the better. Here's what I recommend, as you go along.
Warcry gets its first rune, Hardened Wrath. This doubles the armor bonus to 40%. You will use this until level 60 when I recommend another rune.
Ignore Pain gets Ignorance is Bliss. This rune gives you additional healing while Ignore Pain is active. At 20% that's a lot of healing. If shit hits the fan, pop this and you will do a complete turnaround.
Wrath of the Berserker gets Impunity. This rune doubles your damage while Wrath of the Berserker is active. In other words, you can deal double damage every 2 minutes. This allows you to burn down boss packs and bosses in record time.
Level 40 (but you can do it at 60 if you don't feel the need)
After 40, when you feel like you are getting too close to death for comfort, you have the option to swap the Superstition passive for Relentless. While you will lose some elemental resistance, your survivability will be greatly increased when your health gets really low. This passive has saved me numerous times and allowed me to recover from desperate situations. I'd say it's a must for hardcore builds. In addition, it also reduces your Fury costs by 75%. This skill used to be even better because it reduced costs by 100% but it got nerfed because people were using a build where they deliberately got their health down to 20% so they could kite tough mobs from a distance with unlimited Weapon Throw and/or Seismic Slam with Shattered Ground. This really sucks, IMO, but Blizzard are sometimes dicks like that.
Revenge gets Provocation. You give up some healing and also Fury generation but Revenge now procs twice as often. Believe me when I tell you that the tradeoff is definitely worth it. Now it seems like it's up all the time. Do massive AoE damage! Because it procs more often you can also heal more often (even though the amount is smaller) but this does wonders when you're surrounded by lots of monsters or when you get a boss pack with Plagued or Desecrator.
Frenzy gets Maniac. Each stack of Frenzy increases your damage by 4% for a potential total of 20%. That's a huge amount of extra damage. You'll be forgoing the healing after monster kills but this rune is much better for downing boss packs and tough mobs.
Use Impunity for Warcry. While you'll be giving up some armor, I think you'll gain a lot more by boosting all your resistances by 50%. Don't use this if you don't have enough base resistances because the difference won't be significant.
At level 60, your build will look like this:
It's a very solid defensive build that can also deal a fair amount of damage provided you have a decent weapon. I'm currently in Inferno Act 1 with this build but I haven't really played the Barbarian a lot there due to lack of good equipment. I did kill a few Inferno boss packs with this build, although in truth I am a bit squishy. If you've used this build or have better suggestions I'd love to hear all about it.