I've seen my Klipsch ProMedia 4.1 system on clearence at the local computer shop for $199.00 (in Seattle) and $215.00 at Newegg. These are audiophile quality speakers, very loud and crystal clear. I'd get these unless you need a center channel, in which case I'd get one of what 4ryan6 said^ or something very similar (my reasoning is that, for the same price, I'd rather have a very high quality 4.1 system than a mid-range quality 5.1 system). But that's just me.
<font color=blue>-Toast always lands buttered-side down and cats always land on their feet. So what happens if you strap a piece of toast on the back of a cat and drop it?</font color=blue>