We had a lovely stay in Copenhagen, thanks in part to Morten's listing. The apartment is clean, well equipped (including a Nespresso machine!), and situated a short bus or bike ride away from the city centre. The surrounding neighbourhood is a largely residential area, and thus is rather quiet. The residents of the building are also quiet, so you'll be able to find peace here after a long day out in the city.
It is worth noting that we stayed here during the end of the summer. Air Conditioning isn't terribly common in North Europe, so the apartment was hot during our stay. It would likely be perfect at all other times of the year though.