I also very much like https://www.figure-eight.com/data-for-everyone/ https://www.figure-eight.com/data-for-everyone/. It's not optimized for search but it's a

I also very much like https://www.figure-eight.com/data-for-everyone/ https://www.figure-eight.com/data-for-everyone/. It's not optimized for search but it's an excellent repository of high quality datasets.