To stay on the freeware side:
- I agree with the recommendation above for Norway. Norway Scenic X, Norway mesh (made for FS9 I believe, but it's good in FSX too), Airports of Norway, and Airstrips of Norway. I call this bundle "the freeware european OrbX".
- get that freeware mesh for the Alps (LOD11):
http://www.vf-air.com/MeshAlpes.zip
- get the freeware switzerland landclass that was made for FS9, it will work perfectly in FSX, and will make Switzerland look much better, using the default textures in a very realistic way:
http://www.flightsim.com/file.php?cm=SEARCH1&fname=ebch3tot.zip
With those addons, Swiss will become a very cool place for low and slow flight, especially for gliding etc... The aera around Alpnach, Buochs, Interlaken and Meiringen is especially recommended
For the French part of the Alps, I would recommend the freeware "altiports" that brings sloped runways like Megeve, Courchevel etc...
On this site:
http://translate.google.fr/translat...tf=1&u=http://www.vf-air.com/FSX2.htm&act=url
(translated automatically in English).
Scroll down, it's not so easy to find the sceneries, but you're looking for:
- the VF-AIR object library (
http://www.vf-air.com/VF-AIR.zip )
- the "Altiport" package.
Ah, and the most important thing: you don't think about flying though mountains without installing the FSX mountain mod first

I presented it a long time ago, right here:
http://www.sim-outhouse.com/sohforu...re-addon-for-changing-the-mountain-rendering-!
Be sure to set FTX Central to "Default FSX" before installing that mod.