I have a Logitech Z-5500 that I am selling for $250. They still sound amazing and are great for movies and parties. The subwoofer is huge (10'') and LOUD. And you can get real 5.1 surround if you have an optical or 6 channel audio out on your sound card, since the control pod acts as a receiver. It can also convert stereo sources into 5 channels, so you can still get stereo sound from all speakers by just connecting to your laptop or mp3 player headphone jack. Right now the cheapest ones on ebay are around $300 and $400 on amazon. It comes with all the original items: subwoofer, 4 satellite speakers and 1 center channel speaker, 5 speaker wires, control pod, and 3 1/8'' (headphone jack) connectors that are attached to each other. Feel free to check them out before buying.

4 stars on cnet: http://reviews.cnet.com/pc-speakers/logitech-z-5500/4505-3179_7-31115626.html

I can also include a Creative Sound Blaster X-Fi 5.1 sound card for $40. This thing makes a huge difference. You can check it out for yourself. Thanks.