Yes, its another Berlin thread!

I have a question about where to stay. I have been to Berlin twice already, staying both time at Circus Hostel in Mitte.

This time round i'm going to find an air bmb apartment to rent, in a different area. However like a lot of cities, the feel can vary a lot within a few streets.

Any recommendations on reas or kiez? I quite liked kreuzberg, but i'm still not sure which the best part of it is. Any tips?

Friedrichshain has a good reputation for being cheap and gritty, with cool bars clubs. Anyone stayed there? Again, which areas are good? Also heard good things about Prenzlauer Berg.