Berlin is a collection of small towns stitched together, so your neighbourhood decides what your trip feels like far more than your hotel does.
Mitte — the sightseeing core
Museum Island, Unter den Linden, the Brandenburg Gate and the Reichstag are all inside a 25-minute walk, and Friedrichstraße and Alexanderplatz put every U- and S-Bahn line within reach. It is the priciest district and the emptiest after about 22:00, so you trade evening life for morning convenience.
Kreuzberg and Neukölln — bars, kebabs, canal
The cheapest eating in the city and the densest bar streets, strung along the U1 and U8 south-east of the centre. Good if you intend to be out late; bad if you are a light sleeper, because the streets around Kottbusser Tor and Sonnenallee stay noisy well past midnight.
Prenzlauer Berg — cobbles, playgrounds, quiet
Restored tenement blocks north of Mitte with playgrounds on most corners, and the Mauerpark flea market on Sundays. Roughly 15–20 minutes into the centre on the U2 or the M10 tram, which is the price you pay for the calm.
Practical: pick a base on one U-Bahn line
Berlin covers 890 square kilometres and a 30–40 minute journey across it is normal, so choose a base on a line that reaches whatever you actually came for rather than chasing a central postcode. One AB ticket covers everything inside the S-Bahn ring either way.