I just got a Logitech Z-2300, and it is pretty sweet. 2.1 fyi
The subwoofer alone is worth the price of admission, with bass @ 90% or so, taking the master volume up to about 50% starts shaking stuff off of the shelves.
People in adjoining rooms have started complaining about "That #%&*ing truck idling outside", and I've convinced myself that there has been thunder on cloudy days....and the thing can cause my pants leg to vibrate a foot away from the sub speaker. (All of those anecdotes are with the volume @ under 25%)
Though I must say I only really use them for gaming, hooked to my 360. I've tried them with music, but only from my MP3 player, which needs to have its volume max'd to not sound muffled through the speakers. They work great on game music though....but they are marketed as gaming speakers.
I got mine for almost 66% off, and they're definitely worth it, but again, I didn't get them to blast music.
Edit: Of course now I hear about some sort of Uber-speaker from those in the know, after I make my buy.