i used to have a proper sub and floor standing speakers setup, beat the crap out of any other pc speaker setup i've seen. But had to get rid of them due to space contraints.
I still have my little warfdale speakers (250w RMS each) but don't have an amp anymore, if i get the space i would like to use just them speakers, no need for anything else, there bloddy good, best speakers i have ever had, cost me £150 for the pair ($300 at the time)