https://nfdc.faa.gov/xwiki/bin/view/NFDC/WebHome
http://www.faa.gov/data_research/
http://www.fly.faa.gov/flyfaa/usmap.jsp
http://www.asias.faa.gov/pls/apex/f?p=100:1:
http://www.fly.faa.gov/ASDI/asdi.html
http://www.ntsb.gov/aviationquery/index.aspx
http://openflights.org/data.html
http://www.k12science.org/realtimedatasites.html
http://web.mit.edu/airlinedata/www/Revenue&Related.html
http://space.rice.edu/ISTP/#RT
http://www.brookings.edu/research/reports/2013/07/vital-statistics-congress-mann-ornstein
https://explore.data.gov/catalog/raw/
http://www.inside-r.org/howto/finding-data-internet
http://flowingdata.com/2009/10/01/30-resources-to-find-the-data-you-need/
http://datascientistinsights.com/2013/02/02/data-monetization-road-paved-on-top-of-data-sets/
https://bitly.com/bundles/hmason/1
This is a bundle that gathers public data sets that might be interesting to researchers in a variety of fields in one place.
https://delicious.com/pskomoroch/dataset
http://www.datawrangling.com/some-datasets-available-on-the-web
http://developer.donorschoose.org/the-data
http://www-stat.stanford.edu/~tibs/ElemStatLearn/data.html
http://www.cs.cmu.edu/~enron/
CALO Project (A Cognitive Assistant that Learns and Organizes). It contains data from about 150 users, mostly senior management of Enron, organized into folders. The corpus contains a total of about 0.5M messages.
http://imat-relpred.yandex.ru/en/datasets
http://pages.stern.nyu.edu/~adamodar/New_Home_Page/data.html
http://aws.amazon.com/publicdatasets/
http://www.bus.miami.edu/research-library/free-internet-sites/Statistical%20Data%20Sets.html
http://geodacenter.asu.edu/sdata
http://archive.ics.uci.edu/ml/index.html http://archive.ics.uci.edu/ml/datasets.html
http://image.ntua.gr/iva/datasets/ec1m/
http://www.inf.ed.ac.uk/teaching/courses/dme/html/datasets0405.html
http://www.cs.uic.edu/~liub/FBS/sentiment-analysis.html
https://wiki.gephi.org/index.php?title=Datasets
http://citibikenyc.com/stations/json
http://www.quora.com/Data/Where-can-I-get-large-datasets-open-to-the-public