I was watching the new barbarian skill videos, and I was thinking about the old barbarian's skills.
There was a problem with D2's whirlwind and many other class skills. It was very boring to perform the same skill that does the most dmg over and over. The whirlwind was a problem because you would get sick of seeing whirlwinds.
Much like how there is many different way for a monster to die, to keep killing monsters more fun. You need to do the same for class skills. Relating this more to the many different ways to kill monsters, like with a weak attach, it shows a weak death, or a critical hit, shows a more animated and bloody kill. The same idea works with the class skills.
Maybe when I do a whirlwind, a weak hit would display a short whirlwind with little blood, as where a critical hit may cause a longer whirlwind and some heads get knocked off and more blood. Maybe the wizards chainlighting looks diffrent depending on the damage it caused, or how many targets it hits. Maybe there is 10 diffrent looking chainlighting casting animation? Maybe there is 10 diffrent animations for the whirlwind too, and everything else.
Adding more special effects and ways to impact different objects in the game will help doing whirlwind for the 1,000,000 th time that much more easy.