Purely subjective based on art style, but FFXIV: A Realm Reborn looks fantastic. Firefall is in the same category as well. If you can get into the beta, Black Desert Online has some impressive character creation and the world looks decent most of the time. On the FPSMMO front, PlanetSide 2 is still a favorite. Even with your rig running max everything would still chug in the most intense battles.