Better cable substitue's for my system, for silver ic cables

Any suggestions for cable substitutes/upgrades to what I'm currently using!??? The last couple of weeks I've tried some Harmonic Pro Sillway MKII interconnects in my system (between source and preamp only!!), that made my system just about as neutral, clear and detailed as is humanly possible! (I think?) I was using copper cables by Harmonic, that sound pretty darn good on their own, but this cable made me realize there's more detail/clarity to be had! Only problemis this particular cable seems to be a bit bright in my system (other systems I've heard it work better in).
I've heard talk about some of these Cardas Golden Reference cables, Nordost Vallhala's, NRB(?) cables, and Acoustic Zen's...any one have any comments on any of these cables compared to the Harmonic silver cables????....I want to keep all the detail/transparancy, but loose the zip and sizzle!!!!...any suggestions??? I currently use Sonus Faber Electa Amators, Threshold T200 Class A amp, Pass Labs Aleph L preamp (passive/active), sometimes Tube preamp, and Harmonic Copper cables, with Various sources.
Thanks for any input/comparisons!!!...(I'm only looking for interconnects here!!)