I took a private guide that took me through "Jewish" Berlin, but also gave me a lot more. I've read a (good) guide book before, but he took us to places that weren't in the book and demonstrated knowledge about other things (we've asked him about restaurants, politics in Germany today, etc). The guide's name is Nadav. He is a grad student and also active in the Jewish community there.
I certainly recommend the private tour (it is also not that expensive, and you get a guide all for yourself, in your tempo and customized).
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