Vision of Humanity have created a Global Peace Index that ranks 121 countries according to their level of 'peacefulness', using a variety of internet and external factors. The full list is here, but the top ten most peaceful countries in the world are:
1. NorwayAustralia comes in at #25 and if you're looked for the US, scan down to #96 - between Yemen and Iran. New Zealand would have been #1 but for the orcs.
2. New Zealand
H/T Alastair for the link, though Matheson was talking about this a couple of days ago.