After playing with the GNOME Appearance preferences on my new Mint 8 installation, I managed to completely lose the color scheme, window decorators and other options for the default Helena theme – which I actually liked.
Due to an unrelated incident that I will blame on an abuse of Compiz (which really doesn’t play nice with the Xinerama extension), I recreated my GNOME profile this morning and saved out the default theme. For my own future reference (and anyone else who doesn’t want to nuke their profile), I’ve uploaded the default Mint 8 theme. Extract it to your ~/.themes/ directory and it will appear in Control Center > Appearance as “Default Mint Theme”.
This theme should theoretically work on any Linux distribution with GNOME, as well, but you’ll need the “Shiki-Wise” control set, “Shiki-Colors-Metacity” window border, and the “GNOME-Wise” icon set for more than just the gray and green hues.