Anything with useful audio in it. I dabble in voice cloning, making my own tracks, mixing music and effects, etc. I’m often on the hunt for useful YT videos with high quality audio in them. YT is a gold mine for music and people with nice voices. I would like to do similar things with video content, too, but I don’t know how to do that yet. (Before someone yells at me for ripping off content creators, I don’t use any of this stuff for commercial projects or share it. It’s just a hobby.)