FF:T/C:SOTN probably the two best all around soundtracks.
However, if we're setting the way back machine to when I was a kid...
http://www.midishrine.com/ostepop/ne...hadowenter.mid
The sad, sorrow filled tone just hits home even harder when you think that in this day and age of gamefaqs and hundreds of other spoiler sites, we may never see adventure games quite like it anymore.