What speaker cable made a major difference in the sound quality of your speakers??


I am curious what speaker cables made a big "jaw dropping difference" in the sound quality of your current speakers.  What most impressed you about the difference;  that is, overall musicality, tighter, deeper bass, midrange clarity and soundstage depth, etc.etc. 

Keep the price of the speaker cables chosen or auditioned at  between $800- $1000 or  from  $1000-$1500. Was the cable bought new or used??

  Thank you,   SJ

sunnyjim
Crystal Clear Audio Cables for sure! They beat the Wireworld Platinum line hands down. Especially their Magnum Opus tier:

http://crystalclearaudio.com/products/magnum-opus/
... No silver except the Stager Silver interconnects:

Using 12 gauge Solid Core Copper: home-made, twisted, with bare wire connections; 8-8' lengths for under $14. Setup as bi-wires - it gives me AMAZING SOUND, DETAIL AND DYNAMICS thru my Gershman Avante Garde RX-20s... 
I believe you will notice the greatest improvement in sound quality as wire gauge approaches 14 when starting off with thinner gauge. 12 gauge is the sweet spot for my system. YMMV.