When it comes to casting apocalyptic females David Greene got it right with Bette Davis. Madame Sin is about a shadowy figure with seemingly unlimited funds out for world domination. She kidnaps a CIA agent (Wagner) and through mind control, forces him to assist her in stealing a Polaris submarine. With distinct overtones of James Bond, this film is high on sleek 70's glamor and bleak 70's pessimism. Bette parades around in the most outlandish wigs, makeup and fashions and exudes some serious evil. This was originally a television movie for ABC. It was intended to launch a series which never happened, so after its initial airing in the states it was released theatrically abroad. Look for Denholm Elliot as Madame Sin's henchman.
The film isn't available on DVD, but there was a VHS release of it years ago - that's how I saw it. It's available on iOffer.com and the trailer above is uploaded to YouTube by DVDFilmFun. It's unlikely it will ever see a television schedule again, so the above options are probably your best shot at screening it.
Obscurity factor: 9 (No DVD, just old VHS copies available, never screened on TV, available on iOffer.com)