i liked DS1 , it surely was sth new and impressive graphics wise.
but imo the uniqueness of d2 was battlenet.
I recall DS1 sure offered multiplayer but already few weeks after release it was hacked and cheated to death online, really laughable from MS.
D2 wasnt cheat free, but it hold well for pretty long, 1st huge wave of dupes and cheats only hit it after over a year or so after release - prior that apart the maphack and few abuses it was pretty cheat -free online.
i miss D2 trading and bnet

im surprised no game after that attempted to do sth similar.
Guild Wars is i think made by same guys who invented battlenet, but it goes to full 3d and that's totally different.
D2 isometric view was simplistic, but also great because of that. just enough.