I used to do the same thing, except now I use a set of
Logitech speakers with a pretty potent sub and it sounds great. A little weak in the lower midrange/midbass, but that's typical of a 3 piece system that uses smaller satellites. The logitech site lists them as $150, but a while back, I got the previous years' model for free after discounts and rebates. Only costed me $30 for shipping.
Believe me, it can shake things off the computer desk shelves! I've actually thought about using the 5.1 version for a budget home theater in my room.