I'm well aware of the popularity of West German TV programming in the DDR, despite attempts by authorities to crack down on it. Were there any examples of the reverse being true? Did any East German programs achieve popularity (cult or otherwise) in West Germany?
Yes, East German television was watched in West Germany. Many TV sets sold in West Germany at the time were specifically equipped to receive the East German SECAM colour TV signal in addition to the standard PAL code for this reason.The evening variety show "Ein Kessel Buntes" and the children's evening programme "Unser Sandmännchen" were fairly popular. Sports programming was also watched. West German TV guides carried listings for East German programming.