Since you brought up this year's (well, technically last year's) Youth, you absolutely have to check out the director's previous flick. It actually snagged an Oscar for Best Foreign Language Film—it's called The Great Beauty... here's the trailer link...
Also, running alongside Youth in the competition this year was Lobster, which is way better, starring Colin Farrell... seriously, go watch it... here's the trailer... I honestly don't get why people call it a comedy. Sure, there are bits that might make you laugh, but it's a smart, dark, and totally subversive movie...
Out of everyone else mentioned here, Bergman definitely stands out, but man, his stuff requires a specific mood. His movies feel more like reading a novel or something. I dig Jim Jarmusch, but he just doesn't hit that same level of depth. The French New Wave has some interesting gems too. Check these two out to start... Oh, forgot to mention—not sure if you're into him, but all the Woody Allen movies, which I don't think anyone has even brought up yet, are kind of like that. They're basically crafted by the most neurotic existentialist ever to pick up a camera...