way too many posts to quote.
Generally, the most conductive metals are
Silver
Gold
Copper
Silver isnt used because its too expensive to be used as a wire, and gold is a hell of alot easier to plate with. Silver tarnishes, but doesnt oxidize, therefore conductivity doesnt change. This is why on speaker wire (high end speaker wire) you'll have a silver alloy wire as your positive and copper as the negative (if you ever used copper as a positive you'd notice it oxidizes liek crazy and your signal goes bad)
Gold plating is cheap enough, and doesnt oxidize. It also conducts almsot as well as silver, and can be plated alot thinner.
Copper oxidizes easily with electricity and whatnot.
Brass does indeed have a high copper content, thus brass should be ok. But brass is soft, so be gentle with your
threads.
Steel, zinc, aluminum, etc all conduct electricity poorly (in comparison, of course), thus you dont want your pins to be made of these materials (espoecially aluminum.)
Silver Plated Brass is probably one of the hgiher end pins, I know my nemesis had em, and frankly I liked em alot over brass (but I'm a stickler for brass andi ts appearances)
hope my info is right and I helped ^^