If you have a good hifi, hook it up to that. It's quite easy to do.
I spent a lot of time looking for a decent sounding set of PC speakers and currently use a set of AE Aego M.
http://www.amazon.co.uk/Acoustic-Ene.../dp/B000MN96T6
Slightly more expensive than the price you want to pay but I think you can find them for about £120.
They really are excellent speakers.