I think a lot of game stories are really bland and derivative, they don't need anymore than that so it doesn't get better than that, and any high level abstract stories get shrugged off as a novelty. Personally, it's hard for me to think of a game with the best story as it is to determine a film with the best story, because most of the time it's usually avoiding the worst story as opposed to picking the best one which will usually end up as the "safest" one.