Good and free don't go along well. DDO and GuildWars would be the closest to relatively free and decent quality experience, but if you played WoW for long time they will seem lacking in pretty much every aspect.
Most of the Micro-transaction ones, for unknown to me reasons called free2play, get really expensive if you want to do anything more than just grind for no reason.
Oh and "outside" has crappy shaders, and the character models sometimes look terrible, not to mention really bad writing, poor characters, idiotic plot, annoying permadeath and it takes forever to level up. Its also very expensive in the end.