My personal favorite was FFX mostly because of the ending. It's really what magic is all about, and I thought when (spoiler)Tidus jumped off/flew away at the end(/spoiler) was a defining moment in Final Fantasy games. I also really loved the blitzball mini-game, it's very creative.
FF7 was really good, too. The backstory of Sephiroth as well as Shinra and stuff was amazing. FF8 was memorable, too, and the original Tactics was a really fun game.
And about the song, J-Pop downloads are pretty rare on the internet. Maybe an Asian store like YesAsia.com will have some of his albums.