There are several. Nordbahnhof is interesting because it's been recommissioned since the fall of the Wall, but you can still clearly tell that it was abandoned for 40 years. It feels like it carries the legacy of at least three different Berlins. Although it's unremarkable in every other respect.
I also like the reopened Heinrich Heine station, because it used to be in the death strip and now it's the arrival gate for KitKat, Berlin's best sex-positive club.