I went to Stockholm for a long weekend recently, stayed in the Nordic Light hotel. Pretty nice hotel, rooms were a very good standard and have nice gimmicks, change the mood of the room with light etc.
The ice bar is good, they give you a coat and stuff so it's not that cold. Iced fruit vodka
There was a restaurant just along the road from the ice bar, called Fiske if i remember correctly - it was quit good - kind of arty on the plate food but good nevertheless.
The old recovered Galleon is worth a look for sure, visit the Vasa Museum it was sunken in 1648 and recovered in the 1950's. on Djurgarden and while you're there have a wander round Skansen. There are a few art galleries on the way.