Take a look at logitech speakers. Truly amazing, they have probably one of the best 5.1 systems I have seen in your price range. There was a particular set that was VERY popular but haven't seen them in a while, they may have been disconintued. They were meant to be computer speakers but were so good that people started using them as part of their home theatre setup.
Harmon Kardon also makes a pretty good speaker. They are the only two speaker manufacturers I have ever bought from, on my 3rd set of logitech.
Honestly, check them out. Very attractive desgin as well.
**edit**
These seem to be logitechs most current offering:
http://www.memoryexpress.com/Products/PID-MX3858(ME).aspx
Haven't had a chance to hear them myself but if they are anything like the last generation, you wont' be dissapointed.
Ya, read the reviews in the link above, they sound like they are nice.