We're never going to agree on "The greatest" - we all have our personal favourites but reading this thread is thought provoking and has reduced me to tears on several occasions.
One song that I play evry two or three weeks on my Radio programme (For those interested, "On The Road Again" on www.blast1386.com every Thursday between 1000 & 1300 UK time) I play Pete Seegr singing "Bring Em Home" The horrifying thing is that this song was written during the Vietnam era yet exactly the same kind of wars are happening today!

On reflection, I guess my favourite has to be "Strangest Dream" because it does not come up with clever answers, it doesn't try to apportion blame, it just tells of a wonderful dream. If only!

Eddie