Conan Lord of the Rings Online Tabula Rasa City of Heroes City of Villains Warhammer Online Champions Online Star Trek Online and numerous others...
All have a couple of things in common;
1, They all look better than WoW when run using the appropriate hardware. 2, They all want(or wanted) to be as big as, and as successful as, World of Warcraft. 3, They all failed trying to achieve point 2 (although some are still trying bless 'em).
Looks are not everything. Games need to do more than look good. Substance and ease of use are a good start. And these are just the first of many things that Warcraft does right. I honestly cannot say I have tried Perfect World specifically but I have played all of those in the list above, and none of them had the potential to take me away from WoW for long. I await Star Wars: The Old Republic with high hopes but experience tells me it also will be a momentary distraction.
Perfect world sure does look pretty, but it's no World of Warcraft.