I'm going to keep this short and sweet because his filmography, career and legacy speak for itself. If you haven't familiarized yourself with any of his work you're cheating yourself of one of cinema's finest.
When a film maker as talented and important as Ken Russell passes it cannot go with mention. Had he never made another movie other than The Devils he would have had an important career that would be worth remembering. The Devils is quite simply a perfect film and is one hell of an experience (no pun intended). I'm disappointed to say that I've barely scratched the surface of his filmography but that doesn't take away the sadness I know the film word is feeling. If the world of movies was filled with more Ken Russells the real world might not be such a terrible place.