Subdivizion have a range of free effect racks available. I don’t use them for their sounds but I like using them as templates to build your own racks:
Drum MIFI FX – 9 MIDI Effects Racks to use before Drum Racks and Impulse devices.
Dub Delay – Long feedback dub style delays
Scratch-O-Matic – Old School Hip hop samples for adding scratching over beats DJFX – 3 effect racks for DJ performance or production
Mulitband Freq Splitter – Rack that splits up frequencies so you can apply effects to each frequency band.
Simple Sample Selecta – Useful functional rack. Allows you to audition samples from the browser.
Stereo Width – Effect rack to help enhance the stereo image
The Vowels Rack – Formant Filter Effect rack with EQ Vowel Presets
Yay Filter – Basic control over filter sweeps. Designed to emulate the filter sound used in Electro & Dubstep.