Analytics Vidhya - 25 Open Datasets for Deep Learning Every Data Scientist Must Work With https://www.analyticsvidhya.com/blog/2018/03/comprehensive-collection-deep-learning-datasets/
http://datos.gob.ar/
Australian Government Open Data https://data.gov.au/
AWS (Amazon Web Services) Open Data https://registry.opendata.aws/
http://dados.gov.br/
https://data.buenosaires.gob.ar/
City of Denver Open Data Catalog https://www.denvergov.org/opendata
City of Portland Open Data https://www.portlandoregon.gov/28130
City of Portland Crime Statistics https://www.portlandoregon.gov/police/71978
City of Seattle Open Data https://data.seattle.gov/
Data.gov - US Government Open Data https://www.data.gov/
https://data.world/
DL4J - Open Data for Deep Learning & Machine Learning https://deeplearning4j.org/opendata
https://data.europa.eu/euodp/en/home
Didn't open last time I checked. Try data.europa.eu in a bit in case they are doing a redesign
https://www.gapminder.org/data/
Google BigQuery Public Datasets https://cloud.google.com/bigquery/public-data/
https://www.kaggle.com/datasets
Kairos - 60 facial recognition databases https://www.kairos.com/blog/60-facial-recognition-databases
OpenNASA - NASA open data sets https://open.nasa.gov/open-data/
US Census Bureau Open Data https://www.census.gov/data/datasets.html
US Patent Office's "PAIR" (Patent Application Information Retreval) Data https://pairbulkdata.uspto.gov/
https://data.gov.uk/
data.medicare.gov Open Data https://data.medicare.gov/data
US Department of Labor - Bureau of Labor Statistics Open Data https://www.bls.gov/data/
Other Datasets I've enjoyed https://www.ssa.gov/OACT/babynames/limits.html