ICPSR (Inter-University Consortium for Political and Social Research)--The ICPSR is one of the largest collections of quantitative data in the world. The archives contents cover a very wide range of topics, with household surveys, health conditions and health care, and public opinion being particularly strong points in the collection. Emory's local ICPSR representatives are Ms. Jennifer Doty and Dr. Robert O'Reilly. The ICPSR is also available via Databases at Emory. Please see this notice from the ICPSR on how to access the archive and its data when off-campus.
Roper Center for Public Opinion Research--The Roper Center is one of the country's premier centers for polling data, with holdings dating back to 1935. While the bulk of the Center's data are for national polls, it also includes many state-level polls as well. The iPOLL interface may be of particular use because it allows users to search through surveys at the question level. Roper also has a large compilation of Presidential approval ratings. The Roper Center is also available via Databases at Emory.
Social Science Electronic Data Library (SSEDL)--The Social Science Electronic Data Library is an archive of over 300 datasets covering a variety of topic areas, including Adolescent Pregnancy, Aging, AIDS/STD's, the American Family, Disability in the US, and Maternal Drug Abuse. The archive is well-indexed and allows variable-level searches. This resource is also available via Databases at Emory. Many of the older studies are also available on CD-ROM's in the Data Center.
Harvard Dataverse Network--Harvard's Dataverse Network is an eclectic collection of datasets and data collections, including replication datasets for articles on topics such as political competitiveness in post-war Latin America or the effect of IMF programs on government spending, ongoing research projects on topics such as manifestos of regional political parties and ideology scores of state legislators and perceptions of electoral integrity, organizations such as development NGOs, groups such as networks of economists at different universities, and replication archives for academic journals.
National Bureau of Economic Research (NBER)--In addition to its work on business cycles, the NBER has an eclectic data archive that covers topics such as cross-national technology adoption, manufacturing productivity, financial openness and exchange rate regimes, and economic policy uncertainty.
Council of European Social Science Data Archives (CESSDA)--CESSDA is a consortium of national data archives from various European countries. CESSDA's data catalogue offers a central point of access to the holdings of the individual archives.
Leibniz Institute for the Social Sciences (GESIS)--GESIS is one the premier data archives in Western Europe. It is the principal repository for collections such as the Eurobaromter series of polls in European Union members and the International Social Survey Programme data on social attitudes and issues. It also has a variety of historic data sources, such as a large collection of data from the German Democratic Republic and a similar collection of studies for pre-WWII Germany. GESIS is also a member of the Council of European Social Sciences Data Archives.
UK Data Archive (UKDA)--The UK Data Archive is another of the premier data archives in Western Europe, with a wide-ranging and eclectic collection covering topics such as the finances and trade of the East India Company, the fiscal straits of European governments in the Middle Ages, Orange Order membership in Northern Ireland, and interviews with black immigrants to Britain in the 1800's and 1900's. The UKDA is also a member of the Council of European Social Sciences Data Archives. You can search through its holdings at https://discover.ukdataservice.ac.uk/.
World Bank Data Catalog--As part of its Open Data Initative, the World Bank has opened up access to dozens of its data collections and compiled into a single data catalog. The holdings here range from larger databases covering multiple topics to more narrowly-focused collections associated with particular research projects.
Statista--Statista compiles statistics and indicators from a variety of domestic and international sources, both public and private, and provides those indicators in both tabular and graphical form. While Statista does not necessarily provide access to underlying data from which the indicators are aggregated, it can help you trace backwards to those sources. Statista is also available via Databases at Emory.