(Click here for download info)
From the website:
“CamelCrusher is a free ‘colouring’ multi-effect plugin. It offers two characteristically different distortion sounds which can be blended together to create a wide variety of tones and textures. Great for guitars, drums and plenty more!”
To use this plugin in Pro Tools, you need to purchase the VST-RTAS adapter from FXPansion (highly recommended, and worth every single penny).
(Click here for download info)
From the Sonalksis website:
“The Sonalksis FreeG is an intuitive tool that can be used for a variety of applications to increase the control and flexibility of the signal flow in the insert chain of the host.
When working with digital audio, lack of fine metering and extended signal flow control in the host is a common issue. The intentions with FreeG is to improve the workflow in the host by providing these features in the insert chain.
By providing the possibilites of extended control of amplitude, phase and pan (stereo version) in the insert chain as well as fine metering, with user configurable industry standard parameter options, the range of applications for FreeG is almost only limited to the context of the actual usage and of course, the insert chain.”
I haven’t really found it useful (yet), but it’s FREE!
(Click here for download info)
Sadly, there seems to be some drama behind the plugins from this company, and they may be no longer available.
From the RND website:
“Inspector is a compact, but powerful, analysis tool. From spectral analysis to extensive metering, Inspector gives you a full picture of your audio. Use the spectrum analyzer to get a clear and accurate representation of your mix. The peak and RMS meters, with customizable caution and warning zones, allow you to visualize and quantify the levels of your audio. The balance meter provides a visual indication of the balance relationship between channels.”
Hey, it FREE!
(Click here for download information)
From the iZotope website:
“The ultimate lo-fi weapon, iZotope Vinyl uses 64-bit processing and advanced filtering, modeling and resampling to create authentic “vinyl” simulation, as if the audio was a record being played on a record player. ”
This one is a no-brainer. If you need a scratchy record or lo-fi effect, this is what you’re looking for. And it’s FREE!
(Click here for download info)
SignalTools is a suite of multi-channel metering and analysis tools included in the free DigiRack™ plug-in collection. It comes with all new versions of Pro Tools, but if you have an older version, it can be downloaded for free.
PhaseScope is the only feature of the suite that works with Pro Tools LE, but is invaluable when comparing the output phase of a stereo track or any two streams of a multi-channel output where perceptual coding might take place.
The TD5 analog tape delay has up to 2 seconds of delay time, can sync to the Pro Tools tempo map, and provides a number of tonal options.
(Click here for download info) 
Limitations of the freebie:
All of the limited features of the free version are available in the full, paid version, which at the price ($79) is really worth it.
THC is a highly accurate analog-modeled distortion pedal. THC delivers true analog-like sonic quality. THC can be used to dirty up any audio material — try it on vocals, organ, drums, and, of course, guitar.
(Click here for download info) 
Limitations of the freebie:
All of the limited features of the free version are available in the full, paid version, which at the price ($69) is really worth it.
The CT4 provides clean and smooth gain reduction, with a little punch.
(Click here for download info) 
Limitations of the freebie:
All of the limited features of the free version are available in the full, paid version, which at the price ($69) is really worth it.
The vt3 is a 3-band equalizer with a crisp, unique sound. The vt3 is also extremely DSP efficient.
(Click here for download info)
Limitations of the freebie:
All of the limited features of the free version are available in the full, paid version, which at the price ($69) is really worth it.
Add a little saturation to your mix. Make your drums fuller & louder. Add some grit to vocals. I really like this plugin, and use it on just about every session that I work on.
(Click here for download info)
Limitations of the freebie:
All of the limited features of the free version are available in the full, paid version, which at the price ($69) is really worth it.