A great source for Scandinavian music generally is Ja Ja Ja Music website. They do loads of features on each country, well worth checking out.
http://jajajamusic.com/tag/finland/
I used to love an all-girl band called Drivan. No idea if they're still going.
Bom Funk MCs were another. Albert Swarm is a bit of a gem as are Big Wave Riders. Never really got into Hanoi Rocks.