The most superb coffee I have ever had was at a small joint in Oslo called Stockfleth's. It is up a small side street off the main street called Lille Grensen. We were out in Oslo last June for the SCAE event
and took a course on espresso with Eirik Johnsen (Danish Barista Champion, World No 3) and he works at Stockfleth's. We popped in their several times and Eirik made us some superb cappuccino. Can't recommend it highly enough, try it if you get to Oslo!