I was going to say this
And so the correct answer is this
You should mention what about your system you would like to improve on... what do you like about the system. What would you like to improve.. bass response, accuracy, depth, soundstage... vocals, higs anything...But then I saw this
I have not upgraded to PC's they are stock.
And so the correct answer is this
1) aftermarket pc's.Your freebie rubber power cords are the worst thing you have. Monster runs a close second. Try power cords, interconnects, and speaker cables priced far above whatever you think might actually be worth buying. Not because that is what you should buy, but because that is the way to learn and understand such things actually are worth buying. Once you experience just how much difference these things can make, only then will you be in a position to determine what and how much you think is worth going for.