I'd say the answer is probably Canada which is basically the US with most of the bad things about it greatly toned down (not entirely eliminated of course as Stephen Harper's majority currently proves), and no particular bad things about it that stand out (like the xenophobia in a lot of European countries, censorship-happiness in Australia, nanny statism in Scandinavia, etc.)
New Zealand kind of fits that bill too but it's too geographically isolated for me. (OK from what I've heard the anti-Maori racism can be kind of bad, but not necessarily any worse than the treatment of minorities in the US.)
Sorry, but Canada is much too minor a country in world history to be considered the greatest.