It's funny. A long while ago someone suggested that litz wire sounded better than solid-core, and everyone agreed. Hi-end manufacturers later decided silver wire and teflon insulation also sounded better. Everyone jumped on the bandwagon, and in all the audio rags you'd find the catch-words PTFE and silver littered all over the place. All sorts of exotic wire configurations were touted to best all the others.
The wire war continues, but now that the dust has settled somewhat -at least in the DIY world- it now it seems solid core is smoother and better sounding than stranded wire. Teflon sounds edgy, and unnatural with clangy highs. Silver is also bright, and thin sounding.
Have we finally decided what wires sound best? Is there even such a thing as a "best" wire?
I dunno, but I bought my share of high-priced wires in the past; I still have a set of Silver Streaks and some AQ Lapis x 3 cables gathering dust in a the back room. I've got all sorts of fancy hook-up wire in my mountain of parts but I'm not sure I want to use them anymore.
In the end it all might come down to where you use a given set of wires. I recently bought another pair of MDR-CD3000s because my old (>10y) pair were wearing out. I love the sound of my Sony's and wondered what kind of cable was used in them. It turned out to use, what I guess is now a sonically inferior, litz type cable. I also have a Sun Audio SV-2A3 power amp that I once re-wired with teflon insulated solid silver wire. I know that mod didn't work out well at all. I later replaced the wiring with some copper wire (non-teflon insulation) and got most of the old magic back.
In the end, I think you're going to have to try out various wires and see what you like for yourself.
That being said, I've decided I CURRENTLY hate the sound of teflon coated wire as well as anything with silver in it (even solder). I'm also itching to try cardas litz wire but am dithering because I don't own a solder pot. Then again, I'm also considering just making my own PCBs and getting rid of all wires in the signal path all together.
Graham,
to answer one part of your question, it think any type of metal plated wire sounds unnatural. I think (correct me if I'm wrong) silver coated copper is now unanimously (including myself) agreed upon to sound awful. I tried a gold plated solid copper wire but found that to sound very cold as well.
Really, when will the madness end?