Okay, I played Diablo 3... and you know how it ends, you start season, play for 2 weeks than wait for next patch and next season.
I played Path of Exiles but feels slow and not so polished as Diablo 3 (although fun).
And now I'm stucked, I tried single-player ARPG but it's not the same :/. I expect good story from the single-player games and story isn't really something that you look in ARPG so I decided to look for the other AAA ARPG like Diablo 3... and to be honest couldn't find one... sooo... maybe I overlooked something, maybe there s some shining gem that you could tell me about :)? I would be really glad.
Marvel Heroes is supposed to be pretty good. It went through the same story D3 went through: bad at release and was changed tremendously.
But I'd say you'll find no game as polished as D3, not in this genre. You'd have to broaden your search by the term "MMO" since most ARPGs went that way. There are two games from Asia with potential, which should come out this year. Lost Ark and Lineage Eternal.