Celestia is a free program that simulates our universe. You can freely fly around and visit the different planets and moons of our system and other systems. (add-ons might be necessary)
This web-site contains ALL of the add-ons and scripts that this program can use. Add-ons unclude such things like Star Wars, Star Trek, Babylon 5, Stargate SG-1, 2001: A Space Odyssey and even Hi-Res textures for realistic locations.
Enjoy. Just remember that Celestia takes advantage of OpenGL and is a bit of a resource hog but if your computer can handle it, it's pretty fun. And as an extra tidbit, if you use 3DSM you can design things for this program. Cheers!
The road to perfection is like a damn good RPG. There's a huge intro at the beginning that just leaves you soaked in your own drool, then there's a lot of struggling as your enemies can all kick your @$$ and you never have enough Gil, and finally you get to the point where even the toughest enemies run from your shadow.