if you want the best audio... you need speakers.
what you buy depends on budget.
if you have $300-400+ (or an existing home theater system set up already) i'd go with home theater speakers. this is what some of us with more media oriented setups use (look at the link in my sig).
if you have under $300 perhaps look at the logitech z506 5.1 or small amp and 2.0 bookshelf speakers.
if you have under $200 perhaps the other logitech 5.1 or a high quality 2.1 or small amp and 2.0 bookshelf speakers.
if you have under $100 perhaps the 2.1 logitech or small amp and 2.0 satelite speakers.
if you have absolutely zero space for speakers, perhaps a soundbar attached to your pc.
about the klipsch promedia 2.1..... i had them for a few days...