The Statistical Abstract of the United States, published since 1878, is the authoritative and comprehensive summary of statistics on the social, political, and economic organization of the United States.
Created by the Organization for Economic Co-operation and Development, this source contains primarily economic statistics, but also includes information in other areas. This is an international resource.
Don't let the Data Planet title throw you off. You have reached the right place. Statistical Datasets provides access to public domain and licensed data presented in charts, maps, graphs, and table formats. Can search by topic.
A very interesting site, Wolfram aims to "to build on the achievements of science and other systematizations of knowledge to provide a single source that can be relied on by everyone for definitive answers to factual queries." Broad coverage and fascinating data.