Definitely Berlin! Absolutely love the place. And I wouldn´t constrain myself just to the west-side of city. Personally I like the eastern part a lot more interesting. The area around Alexander platz, for example Hackescher Markt is full of nice restaurants and shops. For cheap beer and great döner kebab head to Kreuzberg or Neukölln. Berlin´s a wonderful city full of history and something for everyone.