As far as film music goes, the first two that came to my mind, Preisner and Kilar.
Wojciech Kilar is one of my favorites, he’s just a terrific composer, not just film. I also have and enjoy film scores by Jan A.P. Kaczmarek and Krzysztof Komeda… I think Krzysztof Penderecki has composed a few film scores, but I’m not familiar with any of them. Wasn’t Bronisław Kaper originally from Poland? Ah, he was, indeed… (I just googled it… unless Google lied to me again. 🙂 ) Though I connect Kaper with the Hollywood Golden Age.