If I had to pick one, it might be How Long Will It Take. It's such a pretty yet melancholic song, and I'm glad Paula Toledo, (the author of the song, for those unaware,) is finally getting recognition and a bit of an audience thanks to the search for that song.
Keep in mind, like greatwhite said, it's hard for me to pick a favorite.
The 2007 JoJo's Bizarre Adventure: Phantom Blood movie. I can't think of another manga & anime franchise, that is as popular as JJBA, which has a lost adaptation.
