Bike art? My two Cell Bikes singlespeeds.
Wonder Woman has been built up as my cafe/commuter bike around a Cell Bikes fixie frame mostly with parts that I had lying around. For some of these parts, this is the third bike that they have been on.
Bumblebee started out two years ago as a Cell Bikes custom fixie, but has had numerous parts upgraded, many of which are now on Wonder Woman. Bumblebee is one of my fitness/training bikes and I often ride it 40+ km.