Bioassay data, described in Virtual screening of bioassay data, by Amanda Schierz, J. of Cheminformatics, with 21 Bioassay datasets (Active / Inactive compounds) available for download.
Data.gov/Education, central guide for education data resources including high-value data sets, data visualization tools, resources for the classroom, applications created from open data and more.
DataMarket, visualize the world‘s economy, societies, nature, and industries, with 100 million time series from UN, World Bank, Eurostat and other important data providers.
DataSF.org, a clearinghouse of datasets available from the City & County of San Francisco, CA.
DataFerrett, a data mining tool that accesses and manipulates TheDataWeb, a collection of many on-line US Government datasets.
Delve, Data for Evaluating Learning in Valid Experiments
EconData, thousands of economic time series, produced by a number of US Government agencies.
Enron Email Dataset, data from about 150 users, mostly senior management of Enron.
Europeana Data, contains open metadata on 20 million texts, images, videos and sounds gathered by Europeana - the trusted and comprehensive resource for European cultural heritage content.
FEDSTATS, a comprehensive source of US statistics and more
GDELT: The Global Data on Events, Location and Tone, described by Guardian as "a big data history of life, the universe and everything."
GEO (GEO Gene Expression Omnibus), a gene expression/molecular abundance repository supporting MIAME compliant data submissions, and a curated, online resource for gene expression data browsing, query and retrieval.
National Government Statistical Web Sites, data, reports, statistical yearbooks, press releases, and more from about 70 web sites, including countries from Africa, Europe, Asia, and Latin America.
National Space Science Data Center (NSSDC), NASA data sets from planetary exploration, space and solar physics, life sciences, astrophysics, and more.
SourceForge.net Research Data, includes historic and status statistics on approximately 100,000 projects and over 1 million registered users‘ activities at the project management web site.