HY-MBMFX Multi-Band Effect

The free version of HY-MBMFX is a 3-band FX unit with a single FX slot on each band. The plugin comes with a long list of available effects (20 in total), including a variety of filters, delay effects, bitcrushers, distortion, modulation effects, a compressor, and even a reverb. The included effects sound very good, as is expected from an HY-Plugins release. Each slot also features input and output volume controls, stereo width and pan adjustment, a brickwall limiter, and mono, solo, and bypass switches. The top part of the GUI hosts the preset manager, A/B testing and undo/redo buttons, whereas the two knobs on the bottom part of the interface allow the user to adjust the frequency band split points.

http://hy-plugins.com/product/hy-mbmfxwinmac/

MaxSynths

MaxSynths have announced that their complete VST plugin line-up is now re-released as freeware. All interested users can download the plugins completely free of charge from the official MaxSynths website.
The developer has released quite a few interesting freebies in the past (PAL-9000 and Sturiophonia are a couple of most recent examples), along with ten commercial VST plugins for Windows. Sadly, it seems that MaxSynths won’t be releasing any new software in the future and won’t be able to provide support for the current plugins either, so they’ve decided to make all of their products free to download and use. Here is the complete list of previously commercial MaxSynths instruments and effects that are now freeware:

• Bass Module – Simple bass rompler with 64 bass sounds.
• Crisalys – A powerful virtual synthesizer with twelve filter types and a mod matrix.
• Cryologic – A sample based instrument packed with a 400 MB sound library.
• DR-910 – A Roland TR-909 style virtual drum machine instrument.
• Latte – A subtractive synthesizer with custom modeled analog style oscillators.
• Nero – Monophonic synthesizer with a built-in pattern sequencer.
• WTS-1 – Simple virtual analog synth with an interesting oscillator instability feature.
• DSP-3 – An easy to use bus compressor.
• DSP-2 – A multi-effect for vocal processing (saturation, compression, EQ).
• DSP-1 – Saturation and dynamics processing for drums.

http://www.maxsynths.com/products.html

Luxonix

Multi Effector

LFX-1310 is a Free plug-in multi-effector including 24 types of algorithm and 3 serial slots. This freeware is the stand-alone version of Effecting Module of Ravity-S & Ravity-R. Every algorithm realizes the very effect you have on your mind, and is fully optimized for low CPU load.

http://sonic-cat.com/lfx-1310/

Big Beauty - Multi Effect

For use with guitar, but useful with any instrument
Amp channel with distortion
Effects include:

Flanger
Auto-pan
Tremelo
Delay
Wah
Reverb
EQ

Midi Learn

http://samcycle.blogspot.com.es/2011/01/big-beauty.html

rf Destroyer

rf Destroyer is a free multi-FX VST plugin. With multiple effect units in one page. Destroyer is useful for sound design and shaping the sound into something more exciting.

Effect units:
- Noise gate
- Drive and Distortion
- Bit crusher
- Pre and master filters
- Equalizer
- Compressor and Limiter
- Flanger and Chorus
- Delays and Reverb

http://rfmusic.net/en/vst_view.php?id=5

LFX-1310 is a Free plug-in multi-effector including 24 types of algorithm and 3 serial slots. This freeware is the stand-alone version of Effecting Module of Ravity-S & Ravity-R. Every algorithm realizes the very effect you have on your mind, and is fully optimized for low CPU load.

http://www.luxonix.com/lfx.html

de la Mancha TRUC live multieffect

truc is a multi-effect VST plug-in, with 4 banks of effects controlled by the movement of 2 pucks. The top puck controls the level of each effect bank, the bottom puck modulates any 4 of 13 parameters within the effect banks. This allows continuous morphing of the sound by moving the pucks to vary the impact of each effect bank.
As well as manually controlling each puck (either by mouse or midi controller) you can lock the pucks together and/or set them to move automatically, either randomly or by a configurable LFO, all in sync with your project tempo.
 
https://delamanchavst.wordpress.com/2013/10/29/the-original-truc-back-for-download/