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

A bit outside the parameters you layed out regarding price points. But for me so far it's been nordost. .just finished doing a demo of TYR 2 power and speaker cables..didn't realize how much of the music I've been missing.has me curious to hear Valhalla or odin. 

Ok, I have to follow up on my original post. I have now installed the Morrow SP-7’s and I have no idea what the other poster was saying about them sounding "phasey". Each system is different however and in my system the SP-7’s are a clear jump in sound quality as compared to the SP-5’s they replaced. What is better? Everything, they are a much more engaging cable than the SP-5’s. My tastes run from rock to jazz and world music and I must admit, these new cables are sweet! I was listening to Neil Young, Live at Massey Hall the other night while my wife was cooking dinner and even she commented that the music sounded great. Of course, she had no idea I had switched out the cables. This is my experience, your results may vary!

Just got a pair of Triode Wire Labs American Speaker Cables and they really are great. I have a full loom of TWL cables and while they were the last piece, I feel they brought about the biggest improvements in tonal balance, more PRAT, and more depth to the stage

Having participated in this thread as it has developed, one thing we can glean is that there are several reputable cable crafters making very good sounding products without having to leverage your home to afford them.  If you have the disposable income to invest in the high priced spread then have at it and hopefully you will be as satisfied as those of us who made more modest, but satisfying investments in cables.

Interesting zacho,
Triode Wire Labs is the cable I plan on using for power cables. I have a mixture now and from everything I have read the TWL cables are great for the money. I too believe that good sounding cables can be had without mortgaging the house.