It's easy to get hyper focused on cables in general and start to think that they are more important than your components, but it isn't true. It's also easy to get caught up in an obsession with the importance of power cords. This happens for two reasons:
1. Your expectations of what a power cord can do are so low, that when you actually hear a difference you are blown away and become obsessed.
2. The speakers and electronics in your system becomes more entrenched and you begin to "tune" the character of the whole system with the last area you play with- power cords.
The truth is what Audiofeil said. You can get much better results with great components and average cables than you ever can with average components and great cables. Many of the best sounding systems I have ever heard used stock power cords.
Speaker cables and interconnects make a bigger difference than power cords, but the experiment that is required to properly demonstrate this is one that most will never engage in. Most of us use very competent signal cables already and then are surprised by going from freebie power cords to exotic ones. If you wanted to do the experiment to see which is more important, go to radio shack and get some 16 or 18 awg zip cord and freebie (red & white) interconnects and replace all of your high end signal cables with those. Then you can compare that difference to your high end power cords vs. the ones that came with your gear. It won't even be close.
