Talking exclusively about what's available here, everyone is going to tell you to watch Seven Samurai and Rashomon and Yojimbo and whatever, they're correct. You already know those ones are great, you've already seen them, you know that Kurosawa is an incredible director. If you haven't, yeah, go watch those now.
But if you have, here's the low key Kurosawa picks I think you should check out:
The Hidden Fortress
This is the movie that George Lucas was copying beat-for-beat when he made A New Hope. The thing is... watching this is just going to make you appreciate both Lucas and Kurosawa even more, because it turns out, it's a great movie either way! Just a real great adventure. Guest starring the most powerful eyebrows you've ever seen on a fired-up princess. I love her.
The Bad Sleep Well
Obviously the best Shakespeare adaptation in the world is Ran, Kurosawa's version of King Lear, but this is him doing a great job at pulling gold out of Hamlet, starring Toshiro Mifune investigating post-WWII corporate corruption, and the most dramatic deployment of a cake at a wedding that you've ever seen in your life. Genuinely interested in using adaptation as an excuse to explore its own conclusions about revenge and evil.
Dreams
Laura is correct. This movie is wild. Watching the absolute master of black and white movies do colour is like seeing Piccolo throwing off the weighted training clothes. If you wanna see some fucking i m a g e r y, you gotta watch Dreams.
Also want to add that I've been able to find stuff from a lot of Japanese filmmakers that isn't readily available in the US. Stuff by Shuji Terayama (a big influence of Ikuhara) and Gakuryu Ishii, who made a lot of stuff with the Japanese counter-culture/punk scene
YES!!! The only Gakuryu Ishii I've seen so far is August in the Water, an incredible vibes-only new age story about a supernatural drought, but it may be one of my favourite movies ever for how it manages to nail its emotional core with some great water imagery. For Shuji Terayama I would highly recommend Pastoral: To Die In The Country, an inscrutable semi-autobiographical bleeding on celluloid with a great score by JA Caesar, of the Revolutionary Girl Utena duel music fame. (They were part of a theatrical milieu that I only really know a little about how it inspired Utena but I really want to learn more.)
If anyone else has any recommendations for other movies by these directors I would love to hear them!