We are travelling with family and hence looking for some good pieces of advice?
Paris is true to its reputation, and it is hard to imagine a more romantic city. The city of love will steal your heart in every aspect. Eiffel tower by night and the stunning views of the city from the hills of Montmartre offer a true eye-feast for visitors.
Ireland I think is a great place to travel with family. It doesn't matter if you're in the happenings city of Dublin or the quaint little peninsula of Dingle, there is no end of things to experience. The culture there is very different than in the U.S. so pubs are kid friendly. The rich history of Ireland is not only educational but fascinating. There's a corner in Dublin where you can almost see major architectural all at one time. Mid evil times, Victorian, modern architecture. It's all there. It's a great place for a road trip, tons of places to stop and look at ruins of old castles. Everyone is extremely friendly. Ireland was the first country I visited in Europe and is my absolute favorite. I will go back again and again and again.
'Europe is a continent made up of 45+ countries. But perhaps by 'Europe' you mean the 28 European Union countries?
Each European country has its own culture, history, foods and (usually) language. All have long histories, with thousands of historical sites & sights and excellent art galleries and museums.
It's impossible to say what the 'best' place is because a) it depends entirely on your interests....and you've given no information about them and b) 'best' is always a matter of personal preference anyway.
You also haven't given any info about what time of year you might want to visit, how long for, a rough idea of your budget, where you can fly into and out of....so your question is pretty impossible to answer.
I'm going to assume you meant the EU countries but can only give you a rough idea of what might be 'best' for you:
Historical sites & sites, museums & art.
Any country but especially Italy (Venice, Rome, Florence, Pompeii etc etc etc), the United Kingdom (Stonehenge, York, Bath, London's sights, ancient cathedrals and hundreds of castles and other ancient buildings), Spain (Granada, Roman remains, Moorish architecture & history, castles), France (castles & chateaux, Roman remains, ancient cathedrals, hundreds of other old buildings) Greece (Athens and its ancient Greek remains, Delphi) ...
Walking, hiking, landscape, scenery:
Cities which are especially popular with first-time visitors:
London, Paris, Amsterdam, Rome, Venice, Florence, Dublin, Berlin, Copenhagen........and more.
Beaches and seaside activities:
Many countries but especially southern Spain and Spanish islands such as Majorca, Cyprus, the Greek islands, Portugal, the Croatian coast.......
From the brief info above ( could have given much more detail) you can see how absolutely impossible it is to suggest the 'best' place.
So can I suggest that you post another question which gives a bit more info about what sort of things you & your family would like to do, how long your trip will be and whether you want to spend all your time in one country or would like to travel around a bit? :-)
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Malta - this post explains everything https://www.buzzfeed.com/erinchack/pics-that-prove-malta-is-the-most-underrated-country-in-t