For pure, unadulterated, visceral entertainment, the "Lone Wolf and Cub" series can't be beat. The acting, directing, the screenplays, and the cinematography are all top notch. The action sequences have to be seen to be believed. Each and every film feature loads of "money shots". Fans of Tarantino will immediately see where he drew much of his inspiration for the "Kill Bill" series. I suspect that these movies were an influence on "Mighty Python and the Holy Grail" as well. Another little known fact is that the manga that this is based upon was also the inspiration for "Road to Perdition".
People with no experience with Japanese cinema will probably find these movies to be very bizarre the first time they see them. They depict a culture whose morals and values are quite different from Western standards. Its not uncommon in these movies for someone to kill, or commit suicide, for reasons not easily comprehended. Examples: in Volume 2, a cult of female ninjas brutally dismember and kill one of their allies, just to prove a point (that they're superior fighters). In volume 6, one thug after another joyfully sacrifice their lives in order to help a princess perfect her killing technique. In volume 3, following a brutal rape and murder, a Samurai attempts to help the criminals cover up their atrocity. His actions are depicted as honorable behavior.
The main character, Ogami Itto, can only be described as an anti-hero. An assassin by trade, he describes himself as evil, a demon, "one who walks along the crossroads of Hell". He will kill anyone for 500 pieces of gold, even women and children. The opening scene in the first film sets the tone of the series, when Ogami, the official executioner of the Shogun, brutally decapitates a toddler. Even so, he is portayed throughout the series as a very sympathetic, honorable character. You will find yourself rooting for him and his son.
I can't say enough good things about these movies. They are so satisfying on every level. You'll get a rush at the over-the-top scenes of violence. You may even begin to question your Westernized notions of morality. Be cautioned though: these movies are not for the squeamish. Volume 1 and 3, in particular, feature very disturbing depictions of rape and murder. Don't say I didn't warn you.