my mains are wired with accoustic research cables (ms320's)
the centre and surround are wired with el cheapo 16 guage "pyramid" brand copper wiring.
I did notice a difference when i wired the front speakers, pretty minor though.
My fronts are 9 feet apart and the cables are 15 feet each. I didn't know how much i was going to have to play with the placement of the speaker when i purchased the cable. I spent half decent money on the fronts because most of my music listening is done on 2 channel.
http://www.plasma.com/acousticresearch/largeimages/ms320.jpg
