And in particular radio based ones check out this site -
http://soundportraits.org/on-air/
I found it yesterday and I have been listening my way through the documentaries as I work. It is mainly an archive of old NPR audio documentaries. Some interesting stuff there. Today I listed to the one about ice pick lobotomies, the one about the Sunshine Hotel, the one about Religion in Time Square and the one about Death Row witnesses. An interesting alternative to my normal music.