One of the most spectacular shows in the world is put on by Mother Nature herself with the aurora borealis also referred to as the Northern Lights. If Norway is on your agenda anytime from September to late March, that's when the skies will be lit up with these fantastic displays. State side, make your way to Alaska anytime from September through late April for the free show.
For me where to see the northern lights has always been a toss between Norway or Finland, but i think northern Norway is probably the best place. The Lapland region is also popular for seeing the northern lights but weather is very often too overcast for taking great pictures. Saying this, the likelihood of seeing auroras is good in both places.
Thanks for the additional information for places to see the phenomenal display of the northern lights. I've added Finland and the Lapland region to my list of places to see.