The entire country of Luxembourg was a big surprise. Scenic and historic and great shopping and movies. It seemed like the mini capital of Europe. When you have a rented car it is also a great jumping spot to lots of places.
I was surprised that such a tiny nation can have lovely rural areas, country inns and totally friendly people.
By train it is also convenience. So, while not part of lots of mainstream tours and guidebooks, my wife and I would always consider Luxembourg a starting point for future trips.
A friend suggested we go there, and he was totally correct.