Diablo 3 not only failed to replicate this excitement, but they took every possible step to ensure that I wouldn't. I got a few of the characters up to max level in a month. Then there is no reason to ever create another character of that class because there are infinite skill respec. Ok fine, Let me pursue the ultimate equipment. Oh wait I can spend a 100 hours grinding or dump $100 in RMAH and get it. There is no point. I might as well be playing Cookie Clicker.
That being said Path of Exile does a good job at giving this experience. Lots of skill combinations combined with deep leveling system works well. I feel like there is still a perfect build out there I can pursue.