The Economist published a chart in April showing some of the (American) colleges with the highest and lowest rates of return on investment over twenty years. The article admits that the study "surely overstates the financial value of a college education" because it compares college graduates to non-attendees without trying to adjust for differences in intelligence, etc., so take it for what it's worth.
http://www.economist.com/news/united-states/21600131-too-man...