We just got back from three weeks in Scandinavia. Great trip. Here's some thoughts.
If you're in Scandinavia, there's this cool kind of simple cooking called humanskost, or something similar; lots of meatballs, gravlax, etc. Even at relatively fancy restaurants, there will often be a humanskost section on the menu, which will often be about half the price of the other selections. Great way to eat good food in a nice restaurant without paying full prices.
Humanskost at Pingvinen in Bergen
Consider going for two short periods - once in winter, once in summer, as it's two completely different experiences. The Norwegian west coast is pretty cool, and I really loved Bergen, despite it being a bit of a tourist town.
Bergen, with great paths that weave between old houses
We were there in late April, which is slightly off-season; great for getting good weather while avoiding crowds, but a lot of things not quite open yet. A lot of the fjord tours and hiking routes don't open up until May.
Fjord tour near Flam
Copenhagen and Stockholm are two must-see cities. Of the places my wife and I visited on our trip this spring (Gothenberg, Oslo, Bergen, Arhus, Copenhagen, Malmo, Helsinki, Tallinn, Stockholm), Copenhagen was probably the biggest surprise, in that we enjoyed the city much more than we thought we would.
150 year old Tivoli amusement park in Copenhagen, spectacular at night
Tallinn is also great; this was the second time I've been there, and it's old-town is still one of the coolest areas I've ever been in.
Tallinn old town