The absolute "best" filter/conditioner for digital

Zd542 is right on the money. The Cable Co. may not carry everything (who does?), but they carry Pure Power+, Silver Circle Audio, Shunyata, Audio Magic, Running Springs, Audience and Furutech. The heavy hitters, in other words.

Dedicated lines...most bang for the buck. Otherwise, Audio Magic

Thanks for the responses!

Two relatively iconoclastic audio personalities have approached the conditioner question and produced modestly priced products that reliably reduced interference, and subjectively cleaned up, shined up, and polished the sound reproduction in my systems.

Mapleshade's power strips - the stealth power conditioners masquerading as humble power strips. These outdid the benefits of a number of other more expensive "real" conditioners.

Machina Dynamica's provocatively and humorously titled "Flying Saucers" for windows which are tiny, home-made looking trimmed pieces of treated copper which even more dramatically improved the sound reproduction of every audio and video device - even down to the level of tabletop CD boombox!
Important note: At no time was any hallucinatory mushroom ingested.

I venture to guess these are among the most cost effective items to try.

Thanks again. I particularly like Zd542"s Cable Company info-i will use it. Also,Brownsfan advice will be followed up.
I agree with dedicated lines- but particularly if you isolate them with something like an Equitech or other balanced power transformer or another type of 'isolation transformer'-they strip away and tremendous amount of noise and can be cheap, used or factory blems or transfomers only that you can box and connect yourself, or any electrician. Be sure to buy over your requirements for best advantage. Even if only digital line is isolated the results are amazing. Always looking for new ideas though,transformers are old school but the balanced are current.