Has a growing tech scene, English is spoken everywhere, a couple of good universities, surpringly affordable cost of living, winters are fairly mild (but long). Definitely has a healthy intellectual atmosphere, with lots of independent study groups/classes. A few hours from Copenhagen, Stockholm, and Oslo. Probably the most "livable" city I can imagine.

Finding rental housing is a real pain, but not because of cost.

Also worth looking at: Ghent, Utrecht, Thessaloniki.