Rankings have lots of problems, but here is an ambitious attempt to look at universities all around the world.
"The Academic Ranking of World Universities (ARWU) was first published in June 2003 by the Center for World-Class Universities and the Institute of Higher Education of Shanghai Jiao Tong University, China, and then updated on an annual basis. ARWU uses six objective indicators to rank world universities, including the number of alumni and staff winning Nobel Prizes and Fields Medals, number of highly cited researchers selected by Thomson Scientific, number of articles published in journals of Nature and Science, number of articles indexed in Science Citation Index - Expanded and Social Sciences Citation Index, and per capita performance with respect to the size of an institution. More than 1000 universities are actually ranked by ARWU every year and the best 500 are published on the web. "
Here are the 2009 rankings.
Two of the top ten are from England (#4 Cambridge and #10 Oxford), the rest are in the U.S. The difference in the "overall score" between #2 and #10 is smaller than the difference between #1 and #2, but this may just have to do with how the scales are normalized. The highest ranked university from a country other than the U.S. or England is University of Tokyo, at #20.
Here is a table of Percentage Distribution of Top Universities by Country with Their Share of Global Population and GDP
Only 15 countries have universities ranked in the top 100, and an additional 24 countries have at least one university ranked in the top 500. The top producers of universities are producing them disproportionately to their share of world GDP or population, for example the U.S. has 55.0% of the top 100 universities, and 30.3% of the top 500, but only 23.6% of GDP and 4.5% of population. (Israel is a big outlier, with 1.0% of the top 100 and 1.4% (i.e. 7 universities ) of the top 500, from an economy with 0.3% of world GDP and 0.1% of population.
I have taught at the universities ranked #1, 25, and 50, and studied at #2 and 7. Based on this limited and skewed sample, and on other universities I know well, I can see that both wealth and the quality of the students are big components of university quality, not always perfectly correlated. (What makes the #1 university so extraordinary is the extent to which it succeeds in assembling so much of both in the same place, and what makes the Israeli universities so remarkable is certainly not their wealth.)
Based on the quality of students from various countries who we see in the U.S., I would guess that, if student quality were the main thing being measured, both Turkey and Iran (each with one university in the #400-500 range) are not getting the credit they deserve. (Many of our students from those places had their undergraduate education at home, and apparently got it at pretty good places; even those who come to the U.S. for their undergraduate education are obviously being drawn from pools of students for whom education is a priority.)
Similarly, there may also be countries where wealth rather than student quality is doing most of the work in putting one of their universities into the top 500, and talented and committed students there might be better advised to study overseas if they can. I'm thinking of Saudia Arabia, with one university in the 400-500 range. A number of Gulf countries have been investing in universities, and it will be interesting to see how well they succeed, and how that changes them if they do.
(A very interesting paper by my colleague Eric Chaney looks at the history of scientific productivity in the Muslim world, and gives some food for thought about what aspects of the general culture might promote vibrant universities: "Tolerance, Religious Competition and the Rise and Fall of Muslim Science")