Ran
Holy shit.
With Ran, Kurosawa proves he's not a master of just his time, but rather a director that can be given every new filmmaking tool and use it to make a masterpiece with it. It just makes you wonder how good his other works (which are already legendary) would be if he had acces to colorfilm from the beginning. Never have I seen a movie that is so in love with color as this one. The fact it turns 50 this year and still looks as if it came out today speaks wonders.
And it's not just style either. The theme of indifference towards human compasion in the name of power is also again executed in a way only a master of his craft could do.
Actual masterpiece. I'll be thinking about this movie for a long time