The Reichstag, the Luftwaffe HQ, the soviet memorial in Tiergarten, Gedächtniskirche, Führerbunker, Topography of terror, Checkpoint Charlie(post-war but still
) , Wilhelmstrasse which was the street where Hitlers chancellery was located and all the other "important" buildings of the third reich. And as you walk around in Berlin, you spot some old houses, left from the war, that still has bullet holes in them.
Michael