The Think Tanks and Civil Societies Program at the University of Pennsylvania has just released their 2009 Global Go To Think Tanks survey, which ranks "The Leading Public Policy Research Organizations In The World". Once again, the ASI has done rather well:
Top 25 Think Tanks – Worldwide (US and Non-US) ranked no.24
Top 50 Think Tanks – Worldwide (Non-US) ranked no.7
Top 40 Think Tanks in Western Europe ranked no.2
Top 12 International Economic Policy Think Tanks ranked no.3
Top 10 Social Policy Think Tanks ranked no.6
The full report is available here (PDF).