Silver Speaker Cables

I love the sound I get from Darwin cables. Check out their Specials section. It'll probably cost more than you're willing to spend but you'll never buy another speaker cable again.

All the best,
Nonoise

I use a "bought used" silver sp/dif cable that was originally pricey but obtained el cheapo. It Sounds fabulous (I think). 

I am using Albedo GEO silver speaker cables and I'm very pleased

The Clear Day Double Shotgun mentioned above by @dill are the lowest priced silver speaker cables I remember ever hearing of ($500 for an 8 foot pair). They are no longer in production (the designer/builder died a few years back), and rarely come up for sale (they're good).

You can try Vogue Audio. I'm using their speaker and power cables and currently have 50% off speaker cable for this month of September. The speaker cable and all their products are 7n silver.