Tigris gnome theme
I wanted to make a theme that suggested elements from OS X, but that did not try to emulate it. Although inspired by another system, I think that this theme is still irrefutably Linux.
Download here: Tigris.tar.gz
This theme requires Murrine and Clearlooks engines.
The Metacity theme uses the buttons from Sauerstoff and the frame from MurrinaLeopardish.