Which powerfilter for best picture on Plasma & LCD

Hi
I am trying to figure out which is the best power filter to plug in the Sony HD TV with to benefit to get the very best & the clearest picture. ( price should be from the best to the best bang for the dollard)
I know they sell many different ones , but I'm looking for best picture quality, any ideal what works best?

Also I see the power cord is a special 90 degree plug to the TV , anyone know if I changed the PC if it would benefit, also where to get one that would plug into the Sony