Best wire to connect amplifier binding posts?

I use DH labs Silver Sonic T-14. Why? Because I have a bunch of it on hand and it's easy to work with.

Skin effect at audio frequencies is a total non-issue. You really don't see the effects until you're up into the MHz+ bands.

Just make sure the wire you use is of good quality and of sufficient gauge to support the anticipated power plus a little extra....

-RW-

RW is partially right with exception to wide bandwidth amps that may actually suffer from such.

I love the sound of solid core copper and always use it in my amps and speakers. Simply sounds better to my ears. Less fuzz and better focus and imaging based on my experience. I build 3 runs of solid core 14-16 gauge teflon coated wire twisted together and like to shield vs not shield.

Makes great speaker cable and power cords also!

As a comparison, it is interesting to look at the wires within speakers. The very high end speakers can have exotic types of wire, but others usually have pretty ordinary looking wire. Of course the runs are pretty short, but it is interesting that people spend hundreds or thousands of dollars on exotic speaker wire that then feeds into very ordinary wire within the speaker. That said, my speaker cables cost 25% of the cost of my speakers :)