I'd go with orz, if you are looking for something to play alone or with friends ,WOW would be the one I'd go for. I've tried so many MMORPG from Guildwars2 to Runes of Magic to Neverwinter ,you name it. At some point, I either ran out of quests to do or after I hit max level,there's nothing really much to do since the game is new.WOW is such an old game with very big maps to do quests after quests ,sure there's not a lot of varieties to do like Guildwars where it has dynamic events and such but WOW at least has an end game.
I heard good things about FFIV and might give it a try sometime soon.