Collector: GroupLens Link: http://grouplens.org/datasets/ Description: A collection of a number of data sets useful for recommender systems. The most famous data set is probably the MovieLens dataset, but there are others as well.
Collector: http://hd.media.mit.edu/ Link: http://realitycommons.media.mit.edu/index.html Description: Data sets opened sources in the hope that it will inspire insights that will help facilitate the use of mobile phones in social science experiments.
Link: https://www.data.gov/ Description: A growing collection of the US Government’s collected data as part of its open data initiatives. Every time I go back I find new data.
Collector: Xiaming Chen Link: https://github.com/caesar0301/awesome-public-datasets Description: A curated list of mostly free data sets that are available. Most of the links are to websites that you can eventually find that data at. Expected to do a lot of digging to find the data, and be happy if you do not need to!
Collector: Vincent Arel-Bundock Link: https://vincentarelbundock.github.io/Rdatasets/datasets.html Description: This is a collection of links for CSV datasets collected from R packages hosted on CRAN. It is not a complete list of all data sets, but it is a good set.