Was just told about this cool open source game, Descent: Freespace 2,
really nice graphics,
some cool UI features and great sound.

http://en.wikipedia.org/wiki/Descent:_FreeSpace

Installers:

MS Windows (Zipped .exe, 19 MB) (Doesn't need Java):
http://www.fsoinstaller.com/files/installer/FreeSpaceOpenInstaller.zip

MS Windows/Linux - *nix/Mac OS (.jar, 26 KB) (Requires Java 1.5):
http://www.fsoinstaller.com/files/installer/java/FreeSpaceOpenInstaller.jar

Zach