There is not a single authoritative list. The World Bank publishes one, the OECD has one. They both list the United States as a tax haven.
If you want one that is a little more US-centric, there is a list of countries in Carl Levin's draft legislation regarding offshore tax havens. I'll provide a link later (once I go look it up again.)
Sorry, in 2011, Sen. Levin modified the bill to remove a listing of specific countries and to put in its place provisions to strengthen FATCA, which requires reporting from all countries.
If I can find a copy of his 2007 version, I'll post a link.