Demon's Souls

Single player is fine as it is. The conservative type people will be playing the game entirely solo because playing co-op is risky business if you die. There is PvP but you won't go out to PvP until NG+ at the very least. That and if you play with randoms, you'll either play with people who don't know what they're doing or people who know everything.

Multiplayer isn't down in any case I believe. I just did some co-op with someone like half a week ago?