Well, my largely unpopular opinion is solid silver with Teflon dialectic from, for example, Homegrown Audio. Different opinions on that. Solid core is the way to go though, for sure, whether copper or silver.
Eric
Emotiva XPA-2, Magnepan MMG (mod), Quickie (mod), JRiver, Wyrd4sound uLink, Schiit Gungnir, JPS Digital power cord, MIT power cord, JPS Labs ultraconductor wire throughout, HSU sub. powered by Crown.