I used to back when the ATI All-In-Wonder was the best card out there. I borrowed a copy of Adobe Premiere from my school to edit the videos. Of course, YouTube did not exist yet, and bandwidth wasn't as plentiful, so there were fewer options in which to use the footage. We'd usually just trade clips here and there. We weren't uploading full playthroughs to servers.
There was one site where I downloaded video game clips from. It was called CHV.net and it's gone now.