@Erik_squires - I use a Panamax M4300 conditioner on my A/V gear. But I could not tell you if it is "effective" in any way - I use it more to isolate (i.e. turn off) the system when away on vacation :-)
FYI: I recently built a 14 gauge helix power cable for the TV, which resulted in darker shadows, with more noticeable details and a brighter, more vibrant picture.
I initially used the Panamax on my audio system at the old house, but found it provided no benefits once I built a power distribution box with high quality outlets and an internal power bus (i.e. it's like a mini distribution panel)
See the end of this page for construction details if interested...
http://image99.net/blog/files/category-002ayou-need-a-good-power-supply.html
Fortunately, my new house seems to be very well wired and I do not experience any noise from the HVAC system, water heater, fridge/freezers/etc..
I did have a house-wide surge supressor fitter to the breaker panel, but that was for protection purposes in the event of blackouts and I did not notice any improvements in system performance once installed
Regards - Steve