English Russia has a splendid selection of the Top 25 Fantastic Soviet Buildings. I think the word they were looking for wasn't fantastic but crazymadmegalomaniacal. They look straight from the imagination of a sci-fi writer with double utopian-dystopian personality. It was hard to pick, but here are my five favorites:
5. Crematorium in Kiev, Ukraine. Crunched by the communists in life, burned to make cement in death.
4. Central research institute of robotics and technical cybernetics, Saint Petersburg. Complete with spacecraft ready to launch at any time.
3. The House of the Soviets, Kaliningrad. "Feed me humans!" it appears to say.
2. Sports and concert complex "Amalir", Yerevan, Armenia. It's actually the entry for the communist aliens' underground spaceport.
1. Recreation and retreat centre Druzhba (Friendship) in Yalta, Ukraine. I can't imagine myself relaxing in this place. It looks more like a futuristic prison.
Check the rest at English Russia and post your favorite in the comments.