The barbarian sucks giant balls at low levels. It's clunky, it's slower than everything else due to being melee-only, fury generators don't generate enough fury or do enough damage, on and on...
Once you hit level 50+, the barbarian starts to turn into A BARBARIAN. You're not fury-starved anymore, you have enough HP to take hits while you round up enemies and cleave them down (I'm playing rend + maelstrom), you can blast through packs just as fast as other classes, and it's generally a WAY better feeling class to play.
Here's my build. Ignore the empty slots as I only filled in the stuff that I think matters for fury generation.
The most important thing I've noticed is that it feels MUCH better when you fill up on fury, push Rend, do 2-3 generators, push Rend, do 2-3 generators... This playstyle combined with the Expectant and Limitless Rage aspects mean you don't really "waste" fury by going over your cap and your Rends do more damage while you keep your fury up.
I take the +24% shout duration (Booming Voice passive) combined with Echoing Fury and Bold Chieftan aspects to get massive fury from shouts.
I'm wearing 100,000 Steps boots that generate 40 fury when I push Iron Maelstrom.
I use the Rapid aspect on a 2H weapon to get +50% attack speed on basic skills. This is HUGE when it comes to generating fury with Lunging Strike a couple times between Rends.
I'm wearing Ramaladni's sword and it generates big fury when combined with the fairly high Lucky Hit % on Lunging Strike. It also makes Lunging Strike do big damages when you're close to full fury.
Rage of Harrogath chest reduces the cooldown on shouts by a lot, so it's a must since more shouts = more fury per second.
This looks impressive, but he was talking about level 50+. I don't have anywhere close to stuff like this at 50, hell I probably won't have half of it by the time I'll get bored of the barb and switch to another class.