The most obscure film I think I have seen all the way through is called the Blind Swordsman's Revenge.
http://www.imdb.com/title/tt1986897/Doesn't have 5 votes, no reviews on there. My copy is clearly a bootleg, probably off a VHS. Badly cropped. No visible subs. I think there has been a VCD release, but no DVD or laserdisc.
Anyway, it's essentially a Zatoichi ripoff made by the Chinese, and also features the flying guillotine and a one-armed swordsman. That's why I wanted to see it. The guy who's the Chinese Zatoichi is actually quite good, but the rest of the movie is pretty crappy.