Toolfarm's Plug-in Finder

Sharpen

Boris FX, Inc. Boris FX - More than 60 filters include motion tracking and image stabilization, as well as self-animating natural effects that easily interact with timeline video.
Boris FX, Inc. Continuum Complete - A comprehensive set of over 150 most powerful, flexible effects including advanced keying, matting, compositing, image processing, distortion, temporal effects and motion tracking.
Boris FX, Inc. Final Effects Complete - Otherwise known as simply "FEC" and recently acquired by Boris from Optibase via Media100, originally developed by Cycore, Final Effects Complete is a collection of over 100 plug-ins.

GenArts Sapphire Adjust, Blur, Distort - Adjust, Composite, Blur and Sharpen, Distort, Warp and Shake

Noise Industries FxFactory - FxFactory is a revolutionary visual effects architecture which powers the largest collection of plug-ins for Final Cut Pro and Motion. Free Download

Noise Industries FxFactory Pro - Noise Industries Flagship Product 150+ plug-ins (bundles the Editing and Motion FxPacks).
Noise Industries FxFactory Motion Pack - A collection of plug-ins designed for compositing task.
Noise Industries FxFactory Editing Pack - A collection of plug-ins designed for editing tasks.

Red Giant Software Magic Bullet Colorista - An inexpensive, smart, fast, color correction tool without needing to fully understand the color wheel.