Well, I think it differs between the setting of the games. Super Mario Sunshine was amazing, one of my favorites, and it was more of a tropical game. The graphics should look smooth, and bright,. Then the setting changes into Space and planets most of the time for Super Mario Galaxy. The graphics for galaxy should be a little different because you're not on a tropical paradise island anymore, you're in space. The graphics should seem darker in the background, and brighter on the platforms and planets. I think there are perfect for the setting, therefore I think there aren't "better" graphics for either games, they both differ.