SNAP(Stanford Network Analysis Project)
Stanford Network Analysis Platform (SNAP) is a general purpose network analysis and graph mining

Bureau of Transportation Statistics

The SuiteSparse Matrix Collection (formerly known as the University of Florida Sparse Matrix Collection)

movielens +  GroupLens

kaggle - Data Science & Machine Learning competitions and open data sets
Use Google's Word2Vec for movie reviews

BSDB (The Berkeley Segmentation Dataset and Benchmark)
Testbed images for image segmentation and edge detection in natural images.

Network Data 
airport-airport  539 airlines 2939 airport pairs

Word count data
to get 3-grams of english text
sample data

MSR GPS Privacy Dataset 2009, March 2017
See the "Downloads" tab:
Seattle region GPS tracking data.
links to some network data, compiled over the years.
co-occurence data among user's access to youtube videos.
friend information among bloggers.

10,000 Facebook status updates of 250 users + personality + Facebook social network properties, including network size, betweenness centrality, density and transitivity.
Cite: Celli F., Pianesi F., Stillwell D., Kosinski M. (2013) Workshop on Computational Personality Recognition (Shared Task). In Proceedings of WCPR13, in conjunction with ICWSM-13.

Image - Video Data
Detection of Moving Objects
identification of changing or moving areas in the field of view of a camera
This dataset contains 6 video categories with 4 to 6 videos sequences in each category

Test Images for Wallflower Paper (background subtraction) February 2017
See the "Downloads" tab: