Well, I don't know of much in particular. But, if you like ambient electronica avant-garde, the world of free albums has tons:
New Netlabels - Netlabel Catalogue
Free Albums Galore
It's take your pick, really.
I highly recommend supporting whatever you can. I mean, after all, these are free albums. By supporting them you are supporting people do it only for the love of the art, something I am 150%.
In fact, I am even a big fan of this type of music. Just not the excess of it.