I need a (PC) 5.1 surround speaker system, with a Dolby Digital decoder.

My friend has the Logitech Z-5500D, which I really like, but it's on the edge of my pricerange ($250 max). I'd like to keep it below that if possible.

Here's what I am looking for:

1. 5.1 (Durrrr)
2. Dolby Digital decoder onboard
3. <=$250
4. Sound GOOD.

I don't need a POWERFUL system, just some great sound. I'm not looking to rattle any walls here.

Any suggestions would be fantastic! (Also, if anyone has experience with the Z-5500D's, that'd be cool too)

Ebay. I got a 6.1, just because there is less demand and they work on 5.1, too. I got mine for 30 bucks. But my sound card didn't work on my system... want it? PM me. $10 + s/h
This is what I got. Good speakers for the low price. I ended up bidding only 15 dollars. http://cgi.ebay.com/Logitech-X-620-6-1-Surround-Sound-Subwoofer-and-Speaker_W0QQitemZ5231952467QQcategoryZ44985QQrdZ1QQcmdZViewItem