I spent two happy and comfortable weeks at Obada's place in Kadıköy. His top-floor apartment has everything you could ask for and more: a terrace with a terrific view, a well-equipped kitchen, and cosy lounging spots. The neighbourhood is peaceful and residential, and very well-connected to both the hip and historical parts of town.
Obada has several rooms available on AirBnB, one of which is bound to suit your needs. I stayed in the small single room that was just right for me: neat, breezy, and very good value for money! You are likely to come across other travellers during your stay, which adds to the liveliness of the flat, but Obada and his guests are also very respectful of privacy if you are looking for a quiet night.
Obada himself is a wonderful man – he has a big heart and a creative soul, and it is a pleasure to spend time in his company.