Best wire to connect amplifier binding posts?

It may depend somewhat on whether you like your existing speaker cables. If you're not looking to substantially upgrade them, then you might want to take your cue from their construction to a degree (whether OCC copper or silver, for example). OCC is much better IME than almost anything (certainly anything that's more conventional, anyway). OCC copper gives more organic pacing and more overall warmth...particularly in the lower mids. Silver in general tends to have cleaner highs and a smooth, detailed and grainfree sound, though tends to be a little cool sounding compared to copper.

People tend to use various geometries in this application and there are likey few, if any that could be said to not work in runs this short. As for gauge, you may want to consult someone with more an engineering backgrond than me, but it will likely depend on the output power of your amp/how long you expect your speaker cables to run, etc. Manufacturers often skimp here, so getting the gauge right can be good thing.

As for insulation, of course: less is more. In an amp, one of the best insulations IMO would be unbleached cotton (like at Parts Connexion), being that it's dry enough on the inside to not be any problem with any of cotton's tendancy to absorb moiture.

But, in all cases, a run of wiring will not likely have a huge impact on the character of the sound (unless something is amiss with your current choice, really), but can't help but imagine that getting it right in these respects is best. Regards.

Use the following link to figure out gauge:
http://www.csgnetwork.com/wiresizecalc.html

This link has minimal voltage 120V, but all you need to know is output power of your amp.

For example if your amplifier delivers 200wpc, you should specify 2 amps. Use the following Ohm's Law formula Power = product of Voltage and Current thus specifying 2 amps you figure out gauge for 240Watts.

If you have large power amp to avoid large gauge of single conductor i'd recommend to use stranded wire to avoid skin effect. The skin effect tolerances you can view from the following chart: http://www.powerstream.com/Wire_Size.htm and if the tolerance level is high for a specific gauge you'll calculate, using single conductor wire will be more efficient vs. stranded but just by very small notch.

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.