Our apartment is on St Hanshaugen, a cosy laid back area with small coffee shops and a nice park. But you can just walk down the hill and you are in the city center. On St Hanshaugen there's good public communication to the rest of Oslo and direct buss to the airport.
Our rooftop apartment is a oase with a big terrace to a green backyard. The high ceiling and bright apartment is isolated from the city noise.