I love Paris, Nice and...(all of France really), and the Tuscany region of Italy as well, been there a lot and enjoyed each time. Austria is beautiful too and many parts of Australia like the tropical north, Tasmania, east coast. Oh, also New Zealand, such a beautiful place, also Vietnam, I liked that a lot too...the UK, Scandinavia...the list goes on.
I've travelled around the world and enjoyed it all so it is really difficult to single out one place.