Problem with online is it requires people to play.
There are only a few games out there that can provide a solid user base for a long time (i.e. Tribes).
Console online games generally die after the generation ends. so that becomes annoying. Hence if you are really into online, I stick with PC as can always find a game.
Single player is preferred by many because if a game is designed well it will not date badly, aka LoZ: OOT which gives it a lot of replay value.







