There is one system that is the exception to that, the N64. Nintendo did such a great job creating Mario 64 and releasing it at the launch of the N64, and no other game really bettered it.

As for Playstation games looking horrible, it is true that many did look quite ugly, but others looked very impressive too. I thought the first Tomb Raider on the Playstation looked great and I sometimes would stand in areas of a level just looking around at the level design. I doubt the first Tomb Raider would look quite as good to me now if I were to play it again.