Old School Runescape Dataset (OSRS)
I have close to 145 million entries into an economy tracking database for the mmo. I am not sure how I should go about uploading it, but I figure it is something that the people in that community would be interested in using. Every fifteen minutes a script collects the active buy and sell offers on the game's market for every tradeable item, and sends them to my database. I've had it running for a little over a year, so it's gotten rather large. I figure even people just wanting to use the data for economy modelling would benefit from such a large data sample.