I'd always do a tour with the Berliner Unterwelten. Very special.
https://www.berliner-unterwelten.de/
The best tour I've ever done was in Tempelhof.
https://www.thf-berlin.de/fuehrungen/
My most favorite Escape Game of all times:
https://the-room-berlin.com/go-west/
Prenzlauer Berg:
https://goo.gl/maps/FdGF3d5eoqjvcT8Z7
Kreuzberg:
https://goo.gl/maps/yBZYJevEURwFDXVc8
Kreuzberg:
https://goo.gl/maps/5shawvdt7c9KuBBN7