I decided to dump some of the hdr files I do use from time to time.
These are the _tonemapped_ jpeg files of the hdri dump #1 files.
These are heavily compressed, tonemapped jpg versions of the hdri, but they are in their original file size.
The openexr high dynamic range images can be buyed here:
a render preview of the individual images can be found here:
These are free to use for commercial / uncommercial projects