Aion: Tower of Eternity was already looking very, very pretty, and the upgraded graphics that have just been unveiled on the official Aion site demonstrate that it's just getting prettier in the move towards Open Beta. The story of Aion is one of struggle between primordial forces, so it's fitting that factions of shadow and light should have environments to suit their nature. Asmodae has no direct sunlight, so diffuse shadows and strong interior lights dominate, while Elysea is constantly sunlit and clear shadows give depth to architectural textures.
Obviously, graphics aren't everything, but this looks like a world we'd like to explore further. With the emphasis in Aion on travel in three dimensions, with winged movement and combat being an important part of the gameplay, it's not surprising that the developers have ensured the environments look interesting from all angles.