I’m quite sure everyone here is familiar with Curious Marc, but I really loved his most recent data spelunking videos:
Marc and his team helped some paleobotanists recover several hundred thousand essentially punch card records that had been stored on 8" floppy disks on a device from the IBM 360 mainframe family. They were able to read the data using an 8" floppy drive attached to a relatively modern computer.
I love this, because there is so much data and software for vintage computers that is slowly being lost to time and obsolete formats. It is thrilling to see something of value being effectively preserved. I have purchased many used disks myself, but typically they do not contain anything of meaningful interest. (I do have some 8" floppies that seem to have some kind of thesaurus data on them in a format that I have not yet identified.)