This song was hard for me to pick because I mean who wants to name a song that makes them cry? But anyways, I searched a bit online to see what others had said, but found I didn't agree with most of their choices. So I turned to opera, which has a tendency to have some very sad songs in it due to the nature of the content. I haven't actually seen this live, only on video and in clips, but La Boheme is an amazingly beautiful opera and the basis for Rent, the modern day adaption of it. I found this online today and had to share, though it cuts off a bit too quick at the end.
Day 4 - A song that makes me sad: Giacomo Puccini - Final scene end of Act 1: La Boheme