It's always weird to me when people talk about video games as if story is the single most important aspect.

Personally I think 2's biggest folly was abandoning the deep RPG in favor of overly-simplistic hack and slash. A mistake 3 somewhat attempted to correct, and for that, I'll take its weaker story because I enjoy playing it much more. And if course 1 blows them both out of the water in terms of RPG gameplay.