The best Indonesian food can be found in the Netherlands. The Hague is tops because it has the largest Indonesian ethnic population. Amsterdam has some very good places - with restaurant Blauw a standout (introducing a new take on Indonesian). They are also in Utrecht and The Hague.
http://www.restaurantblauw.nl/

In the US the best places can be found in Washington DC (again the largest population of ethnic Indonesians)-there's also a food truck - and Queens, NY. Indo-Java is one of my favorites. Very basic but authentic.