My personal objects of fascination are the cardboard boxes with the old records for 1€. It's interesting to compare the selections in different cities, or even in the different parts of the same city, like Berlin.
In the west, at the Tiergarten Trödelmarkt, for example, in every second box you will find an EP of Dschinghis Khan with their song "Moskau" from 1980. That was one of my grandfather's personal favourites. He would listen to it on repeat, and I would usually be somehere close. I heard it so many times that i memorised the german lyrics without understanding a single word. This track was banned in the USSR, noone knew exactly why. It was kind of dangerous to listen to it, but everyone did all the same. Years later, already in Germany and speaking the language fluently, I've heard the song again, realised I could sing along, but also finally understood the lyrics... and they were quite harmless. Dschinghis Khan were the german answer to the Village People, playing less with gay elements and more with ethnic/exotic. Today their record covers look slightly ridiculous.
I bet that every fleamarket of the eastern part of Berlin will offer you dozens of records by Dean Reed, one of the very few americans who chose the career of a pop-star in an unlikely place, the GDR. That was quite an extravagant move. He became known as the Red Elvis, recorded a bunch of awful country albums in the Chech Republic, shot some cowboy movies, sang Hava Nagila for Jassir Arafat, toured Siberia and commited suicide by drowning.
I wish Dschinghis Khan would have featured Dean Reed in one of their songs, I would have bought such a record.....sadly, they never did.