Jagjit is the king of sad singers. He is responsible for spoil many young life from his very sad song. His every song is most sad song ever which make mad the young generation.
I don't have any particular choice for it and can choose any of them that is based on some saddest lyrics. Michael Jackson's song man in the mirror is ever sad song for me.
I think the most sad song is meri kismat mai tu nhi shayad. Its one of the hit Bollywood song. These song also got award.
Canon by Pachebel. You can listen to the song here. http://www.mp3-codes.com/play/237315/Pachebel-Canon_In_D
Trying to remember the exact name...but I think it was the Whiskey Blues or something like that...I hate country but that thing gets me whenever I hear it. A couple splits up and the guy ends up drinking himself to death missing her, and she drinks herself to death over him.