The general recommendations are going to be some Bose product that I won't recommend and people will make jokes about. The Sound Sticks which people seem to be giving a lot of credence to these days. I'll recommend the Altec Lansing FX6021, which will lead to another discussion. Then someone will recommend the Logitech Z-2300. At this point, someone will recommend that something from Wal-Mart that costs $25.00 and they will swear it that's greatest thing ever. Someone will then recommend Bose and get flamed, followed by the comment about get yourself a good set of cans (headphones), because those will always sound better. Somewhere along the way the M-Audio's will be thrown around, followed by people like me recommending a different set of pro monitors, followed by another Bose posts. There are a couple of intangibles: someone might recommend the Klipsch Pro Media 2.1, Creative's T40 or some other Logitech that's probably not as good as the Z-2300s. After about 20 posts or so, the general consensus will be reached by a couple of users, you should probably just go hear them for yourself, making the thread well...you can decide...
Now you of course would have known all of this if you searched, but I did all the work for you.
Speakers Discussions Are Rampant:
Here is one thread for $100 USD. Good Discussion.
USB Speaker Discussion
Here
Here is another discussion
Wireless Thread Here...although it diverged.
2.0 Discussion
Here
$200 Discussion Here