FxFactory offers a bunch of free visual effects filters, transitions and generators for After Effects.
You need to first install FxFactory, then you can go ahead and install the free AE plug-ins one by one.
The free plugins for AE listed below are just a small selection of the ones available. The complete list of free AE plugins can be found here.
Barcode by Yanobox
Yanobox Barcode generator creates animations that are European Article Numbers aka EAN-13 barcodes.
Star Titler by Noise Industries
Star Titler allows you to easily recreate the look of the opening titles made famous by the original Star Wars movie in 1977.
CoverFlux by idustrial revolution
The Coverflow style scrolling image generator plugin for Adobe After Effects. The plugin also works in FCP and Motion.
Freebie Pack by idustrial revolution
Five free plugins for AE, FCP and Motion: MultiSpace, iSight Live!, Rack Focus, Opposites and World.
Tutorial: idustrial revolution freebies pack
Get idustrial revolution Freebies
PHYX Freebies
Two free plug-ins for After Effects, FCP and Motion ColorChannel and EdgeSharpen.