Solar System 3D is really great. Even the free version, Solar System Lite. When you touch the screen you can change the 3D perspective. You're gonna want to leave one home screen completely blank so you can play with it. Even 'though I don't use a live wallpaper, I went ahead and bought the paid version (only $1.43) just to throw the creative developer a little bit of support. It's a battery hog, so I use it for entertainment and education with my kids.