Both are not necessarily sad by themselves but the context of what is happening when these songs played almost maked me cry, eyes watered up, I don't really cry.
Pretty awesome how Final Fantasy leads the way in pretty much every video game music genre or perhaps more fittingly, Nobuo Uemetsu. For me, there are many beautiful pieces out there but it's very hard to ever top Aeris' theme, in my opinion the only game to come close is the music of Xenogears. Here are some good ones :)