Kjaerhus classic audio plugins: an amazing collection of free vst effect (chorus, flanger, compression, equalization...)
A0 parametric equalizer: one of the best free equalizers available.
Posifhopit: an other great free equalizer.
izotope vinyl free vst plugin Izotope vinyl: an excellent vinyl simulation vst plugin.
Tape stop: an amazing free vst plugin that emulates the sound of a tape recorder that stops.
Voxengo Boogex: guitar amplifier plugin.
Camelcrusher: amazing distortion plugin for guitars and drums.