http://www.tokyodawn.net/tokyo-dawn-labs/ – TDR Feedback Compressor II, My absolute favourite freeware compressor.
http://varietyofsound.wordpress.com/ – Free VST Plugins from Bootsy, some studio grade stuff for free.
http://www.plugandmix.com/ – Professional and Affordable Plugins some of which I use on mixes every day.
http://bigbitefx.com/ – Guitar Effect’s Pedal Manufacturer from the UK.
http://www.pensadosplace.tv/ – Awesome tutorial and interviews with music industry guru’s with Dave Pensado (Grammy award winning mixer)