I lived (studied) in Denmark in 1982...and did some traveling to
Germany, Holland, Switzerland...I don't think Europe has changed in
terms of "when is the best time" to visit the countries. I would
suggest to visit Europe during summer hoilday (July, August), warm and
a lot of tourists. Pick a starting point (one city in Europe) and
decide next which countries to see. Choose Eurorail for moving from one
country to another. Stay in youth hostels. Have a nice trip !!!