Three Colours but no Dekalog? And while we're on Kieślowski, Blind Chance uses the same device and is an interesting take on Polish society in the late seventies.  Sticking to Polish stuff, Wajda had done some good movies, e.g. Man of Marble is excellent. His early neorealist trilogy - Pokolenie (Generation), Kanal, and Popiól i diament (Ashes and Diamonds) is good if a bit dated and his study of nineteenth century industrialization Promised Land is very good as well. Roman Polanski's Knife in the Water was even better than I remembered when I saw it again recently.  For a fun thriller on the transition to democracy see Psy Dogs - about ex secret police 'adjusting' to the changes.