Here we go:
just a share of this really useful link:
http://www.resoundsound.com/25-best-free-vst-au-plugins-pc-mac-2013-part-1/
http://www.resoundsound.com/25-best-free-vst-au-plugins-pc-mac-2013-part-2/
http://www.resoundsound.com/25-best-free-vst-au-plugins-pc-mac-2013-part-3/