Wow, I 3rd first post in a row :-)
My favorite is my hometown Piter, I am biased, but Saint Petersburg has so much history and great arctecture that Soviets let stay, as well as parts of the city with towering prefabricated concrete Apartments that were the signiture of Soviet Times. I live in city centere and all I see is beautiful pre-revolution buildings and a fortress. Palace Square is also so much nicer than Red Square :-)