I upload obscure music that isn't already on youtube so I can access it if I feel like playing it at friends' houses or something, and to hopefully do the other three people in the world who listen to this stuff a favor.
Also have a few Anime Music Videos I made back in the day with songs I don't necessarily even like anymore. I find it somewhat amusing that the only one that was taken down for copyright infringement was an In Flames song off their very first album, and not something more mainstream.