If you are thinking about visiting Christmas markets, I would definitely recommend Strasbourg (Alsace, France). I was lucky enough to spend one Christmas there. It was beautiful! It was so cold (minus 18 degrees!!) but the breathtaking scenery made me forget how cold it was! Leaving in Brittant, we are not used to the snow and temperatures below zero.
We actually visited the centre of Strasbourg on Xmas day after a long lunch. It started to get dark, the place was packed with happy tourists from all over the world. A great memory!