Stable benchmark dataset. 20 million ratings and 465,000 tag applications applied to 27,000 movies by 138,000 users. Includes tag genome data with 12 million relevance scores across 1,100 tags. Released 4/2015; updated 10/2016 to update links.csv and add tag genome data.

Also see the MovieLens 20M YouTube Trailers Dataset for links between MovieLens movies and movie trailers hosted on YouTube.