I will readily admit I'm obsessed with Berlin. For any other Berlinophiles out there, I wanted to share a great resource... Slow Travel Berlin. It's an organization geared toward encouraging deeper exploration of the city. Its primary founder is Paul Sullivan, who writes the excellent Rough Guide to Berlin. Slow Travel Berlin mostly died a couple of years ago (much to my chagrin), but it recently has been resurrected.
The website is great. It has an eclectic treasure trove of intelligent articles from a look back at the Palast der Republik to an interview with a former DDR photographer to a magical schnitzel discovered while walking home from the Olympic Stadium.
Looking for some reading related to Berlin? The articles 10 great books about Berlin and 10 great books about the Berlin Wall have more than the "usual suspects."
I'm fortunate to have a hard copy of Slow Travel Berlin's 100 Favourite Places that I bought back in 2015 -- now available only in ebook form. I recommend it to those interested in seeing more than the typical Berlin sites.