Get the Klipsch ProMedia Ultra 5.1, I have heard both the z-5500s and the ultra 5.1s, and they just slightly edge out the z-5500s out on sound quality, they have a dual driver sub, and every satellite has a tweeter. The the bass is more impactful, tighter, and more controled than with the z-5500s. Now the average joe who listens to mp3s encoded at 128kbps with the sereo speakers that came with his computer probably won't be able to tell the difference between the two sets, but the Ultra 5.1 is just ever so slightly better, and as I stated above, I have owned both sets, and I like the ultra 5.1s better.
never get creative speakers, they suck.
so, umm, err yeah