What did you love about it so much? I'm not even sure I'd put it in a top 20 of the genre, let alone as my favorite game of all time in general.
What would you call the top 20 of the genre? And what do you mean by "the genre" in this case? If the genre is CRPGs (which I guess I would consider to be just about any western, non-action RPG), I think I'd definitely have it in the top 20. At one point, it was my 5th favorite game of all time, but too many good RPGs have come out since then, so now it's not. But still in the top 20, certainly.