Japan.

There are many countries in the world.

And, expatriates from western countries live in many different 
countries, for various reasons.

However, Japan seems to be the only country that people dream of living 
in for the sake of living there.

Look at the internet forums regarding living and working in Japan... 
there are thousands of posts from people seeking any way possible to 
make a living of any sort in Japan. The aim to live in Japan IS the goal 
in itself.

Of course, some people have a strong interest in a particular country. A 
"Francophile" might dream of living in France. But the intensity and 
widespreadness does not approach that of Japan.

Why is this. Obviously there are many unique and interesting things 
about Japan... but same for any country.