Some excellent suggestions, but no mention of my favourite director, Kurosowa. OK some mentioned Seven Samurai. The best 2 though, I thought were:
Kagemusha, the opening shot of a warrior running down a castle, lasts about 8 minutes and stopped me dead in my tracks.
Ran, his version of Macbeth, very suitable for the era of cruelty and deception in the time of the Shoguns