Choosing Strasbourg for this list was a no-brainer because it is the Christmas setting personified. I have never seen a city more decorated at Christmas than Strasbourg. Not one shop window or street is without twinkling lights, window decorations, or market stalls. You can barely take it all in, there is so much to see. Don’t get me wrong, I have visited in summer and enjoyed sitting out by the river, and loving the atmosphere of the old town, but if you only get to visit once, make it December, and take in Christmas in Strasbourg. It has to be seen to be believed. And don’t think that it is too much or tacky. Not at all. It is simply perfect.
Pro Tip: While there are big Christmas markets around the cathedral and on the main square, concentrate on the smaller ones in Petite France, the really old part of the old town, where half-timbered houses, covered bridges, and tiny squares add that extra-special ambiance.