Alien Mars did a great job of collecting Photoshop plug-ins here, I gathered the links, planing to do a review later.

http://www.autofx.com/
http://www.flamingpear.com/
http://www.avbros.com/
http://www.humansoftware.com/
http://www.panopticum.com/

http://www.focusmagic.com/
http://www.agetechnologies.com/
http://www.alivecolors.com/
http://www.andromeda.com/
http://www.axionfx.com/
http://www.boxtopsoft.com/

http://www.filtermeister.com/
http://www.fixerlabs.com/
http://www.fnordware.com/
http://www.frischluft.com/
http://www.icnet.de/
http://www.artistic-effects.com/
http://www.pegasusimaging.com/
http://www.zaxwerks.com/
http://www.vertigo3d.com/
http://www.alienskin.com/

http://www.digi-element.com/
http://www.extensis.com/

http://www.jasc.com/
http://www.medialab.com/
http://www.righthemisphere.com/
http://pixologic.com/
http://www.xaostools.com/