Why not try the Baltic states? Lithuania, Estonia and Latvia are beautiful countries with a long history.
Coastal Italy is nice too - particularly the southern end.
Paris France for Eiffel Tower and museums
England, Despite the occasional bad weather there are some nice places :)
European Country looking for an affordable destination with very good weather during the month of May will be happy to know that the list of possibilities is long. There are fascinating cities in most regions of the world that are worth a look, as well as many affordable beach areas for those looking to relax in the sun.
Fennoscandia for the landscape.