The Zatoichi films are pretty good. Hanzo The Razor films are even better as there is some comedy mixed in with the action. They torture captive women spies by dropping them down on Hanzo's monster cock. 
I've seen all 3 Hanzos. Shintaro Katsu was also good in the Lone Wolf and Cub movies.
I think the Lone Wolf movies were part of a longer series that they edited down down into a few movies. Hanzo and Lone Wolf were based on Japanese comics.
They edited 2 Lone Wolf movies down to Shogun Assassin. I watched every Japanese exploitation movie I could find around a decade ago and need to read up on them a little.