Which power cord to upgrade first?

Tvad, your suggestion comes right on time. I need a cheap cord now while I am waiting for my Audience cords to arrive. I have all the stock cords burried somewhere in the closet and I'm too lazy to dig in there for them.
I may consider the Volex.

I would agree with the earlier post of having a dedicated line first, then outlets, and then power cords.

I did it that way, and the dedicated circuits were the most dramatic improvement of anything.

I have a dedicated 20A circuit for my amps and one for my front end.

Thanks for everyone's thoughts. My system consists of:

Denon DVD2200 (DVD, CD/SACD)
NAD T763
Spendor S5e
I am running direct 5.1 from the Denon with Audio Note AN-S silver interconnects
Speaker cable is Luminous Renaissance

Obviously, my system is a little far from high-end, so perhaps a PC upgrade will have little impact at this point?

Tvad is dead on; power cords would be diminishing returns at the point you are at. Definitely save for component upgrades - much bigger bang for buck over time.