Harvard Dataverse Network (DVN)
Harvard's Dataverse Network is an eclectic collection of datasets and data collections, ranging from replication datasets from articles to institutional data collections. Many development NGO's and research organizations use Dataverse, including the Jameel Poverty Action Lab, Population Services International, the International Food Policy Research Institute, and the Center for Global Development. Dataverse also hosts more esoteric, specialized data collections, such as this collection of data on financial inclusion and access in Kenya.
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.
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. You can also search for World Bank data by country or by looking for specific indicators.