I have a set of 5.1 Logitech Z5500 speakers for sale. I have been using them for a couple of years. I have recently moved houses and there is simply not much space for the speakers at my new place. 

The speakers are in perfect condition, they sound great, the bass on these speakers is pretty much unbeatable. These speakers are highly recommended if you are a serious gamer. They are THX certified. The sound on these speakers is unbelievable. Its just awesome listening to rock music, watching star wars or playing COD (or Left 4 Dead). Just do a quick search on Google for Logitech Z-5500 and you will see many reviews about them. 

I dont think you can buy these in stores anymore (if you can, it would be priced above 600!)

The speakers have a multitude of inputs; Direct input from the computer, SPDIF digital input, Coaxial, line in. I have the remote for these speakers as well. I have been able to connect my MacBook to these speakers and get full sound from them. There is a cable which allows you to output Digital music from your MacBook to these speakers using SPDIF. 

You can even use them as home theatre speakers. My last set up, I had them connected to my PS3 using the Optical output. It is awesome watching Blu Ray movies on these speakers!

PM me if you are interested. Priced at $480 or new offer.