There's the Zatoichi series. The first, The Tale of Zatoichi (1962) is required but I gave up after the first three. @falidorn@lemmy.world mentioned that Kazuo Miyagawa was the cinematographer for some of them in this thread.
The Sword of Doom is a classic. Same for Harakiri. Maybe Bushido: The Cruel Code of the Samurai, too (depends on one's tastes). If you don't want to get stuck in the 60s, Twilight Samurai is more modern.
I'm forgetting some that are worth a mention, but I'm totally skipping some titles I think are just 'meh'.