Third party plug ins for Adobe CS5, both After Effects and Premier. I am aware of New Blue, Planet Red and Boris. Are there others?

I think you mean Red Giant. Planet Red is the camera forum ;)

Genarts Sapphire and Monsters range are some of the really fancy and expensive effects packages.
"Effects" is like a a category of its own though. Quite often stuff you see now is made by or in conjunction with specialty 3d and particle suites which the effect suites don't have.

Check out toolfarm.com. They sell plugins from a number of vendors for AE and Premiere.

Here's a list by Adobe, too: In depth | Adobe Premiere Pro CS6 (http://www.adobe.com/products/premiere/extend.displayTab4.html)

Third party plug ins for Adobe CS5, both After Effects and Premier. I am aware of New Blue, Planet Red and Boris. Are there others?

Take a look at Tiffen DFX video filters

Tiffen Dfx Video Film digital effects plug-in (http://www.photo-i.co.uk/2012/10/tiffen-dfx-videofilm-plug-in-review/)

See these pages for details of plug-ins for After Effects and Premiere Pro:

plug-ins for After Effects CS6 After Effects region of interest (http://blogs.adobe.com/aftereffects/2012/05/plug-ins-for-after-effects-cs6.html)

plug-ins and third-party hardware for Premiere Pro CS6 Premiere Pro work area (http://blogs.adobe.com/premiereprotraining/2012/05/plug-ins-and-third-party-hardware-for-premiere-pro-cs6.html)