I think the lines between "Western" and "non-Western" are very blurry in Eastern Europe, but generally those countries that followed Eastern Orthodox churches and used scripts other than the Latin alphabet are much further away from Western. Countries like Poland, whose cultures are histories are both intertwined with Eastern Europe and Western Europe, really blur the line.
Then there's Greece, the outlier, which many like to claim for Western culture based on recent history (participation in NATO) or some strange notion that ancient Hellenic influence on the development of modern Western culture makes Greece a Western country, despite the fact that pre-modern Greek history and modern Greek culture, religion, language, and geography are just as distant from Western Europe as Russia's is.