cable upgrades , real or rip off

Spend your money on the equipment!
Spending it on interconnects/PC cord is no a wise choice of investment.
Though I do agree that the better interconnects and PC cords DO sound better, they are not the best bang for the buck when one could spend one's cash on better electronics that will be better than the lesser electronics and a bunch of expensive interconnect.
I stick with entry level interconnects that are well known like Nordost Blue Heaven, or Kimber PBJ/Hero.. even KCAG.
Though if you have an amp or whatever you really enjoy, a cord might do something for you...
As for chairs etc, I find the biggest change is when I wrap the speaker cables around my neck. Tight enough and the sound just makes me swoon! Whoo Hoo...
(8^Q...

I think Elizabeth is correct, that is until one reaches the point where changing equipment represents more of a horizontal movement than a vertical improvement.

At that point, a system, regardless of its specific make up (of components, speakers, cartridges, etc) is definitely capable of revealing the very real differences in cabling. And so I believe that is the time to begin this exploration, and probably not before. I also believe that at this point in system development, no further changes should be made in equipment until the cabling is brought up to a similar level as (the already high quality level of) the equipment.

Perception is reality: you decide.

I'd rate the cable importance in this order.
1 - IC from source to pre
2 - IC from pre to amp
3 - Speaker cables
4 - Power Line conditioners(not cables but still relate)
5 - Power cords

The best interconnect should reside between your source and your preamp(or integrated).
And by the way, good cables make a difference once the rest of your system is good enough to show it. Otherwise with crappy components don't expect difference between cables to be big or to exist at all.

I basically agree w/ Audphile's ranking, except I think #4 should read: Dedicated circuits (if possible) and then powerline conditioners (if necessary.)