Another vote in favor of Prague from me. It's true, the city can get enormously crowded at any time of the year and day, but this is true for other cities as well and people seem to criticize only Prague for it. So if you want a quiet city just for yourself without the crowds, this is not the place for you to go. But for those who don't mind a few other tourists, Prague remains one of the most beautiful cities in Europe. The Hradcin with the Cathedral is really a great sight from the city below, and the old town and Charles Bridge are must-see sights as well. A daytrip to any of the older Czech cities or the many castles around Prague will help you get away from the crowds at least a little bit.