What are the best Room Accustic Treaments members have found?

Plus one for the SR products. They have transformed the sound of my system, or, more correctly perhaps, they have transformed the sound of my room. 

Thanks for all the input my fellow Addicts

You got your Skyline diffusers. You got your Echo Tunes from Michael Green. You got your Acoustic Discs from Golden Sound. You got your tiny little bowl resonators from Franck Tchang and others. You got your crystals and you got your Mpingo disc from Shun Mook. Don’t shun the Mook! You also got your hand built Helmholtz resonators.

Synergistic Research HFT may transform your room, but they probably don't do much to improve the acoustics.

Just as some cables are gross tone controls, so are SR products effects!

davidrolson, forgive me if you already know this. Room treatments generally address damping (absorbing) or redirecting sonic reflections. if you do some research, you'll have a good handle on what your room "needs" Many of us have made absorption panels with OwensCorning foam insulation installed in frames with nice fabric covers. It sounds like you've made the first step to realize you want to treat your listening room; many never do that and IMO that's the primary building block to a good listening experience. Good luck.