If you use your PC for games, music, movies, TV, or anything else involving your ears, nothing beats a set of surround-sound speakers. Buy.com has the Logitech X-540 5.1-channel speaker system on sale for $44.99 shipped (after a $20 mail-in rebate).
The X-540 includes four wall-mountable satellite speakers, a center speaker (which has a clip for attaching to flat-panel monitors), and a subwoofer--all of which combine to pump out 70 watts of audio power. The wired remote includes a headphone jack so you can plug in when the neighbors start complaining.
CNET never officially reviewed the X-540, but users gave it an average score of 8 out of 10. And Buy.com's customers collectively rated it 4.5 stars out of 5. So if you don't mind waiting on a rebate, here's your chance to score a sweet deal on some surround-sound goodness.