When this issue comes up, I often hear the somewhat apologetic excuse that the countries at the top are there because of some combination of 1) rote memorization, 2) teaching to the test, 3) highly standardized systems which generally don't apply to the U.S. systems. Since my children were educated in the French system (in the US), I know there is some truth to these assertions. But, while it may be true in some or most countries that perform well in tests, I have read much about Finland's system that suggests in many ways the opposite approach is taken and yet with obviously good results (e.g. http://news.bbc.co.uk/2/hi/programmes/world_news_america/860...).
I'd be interested in hearing from Finnish HNers on their impressions of their educational system.