I haven't tried any of them but personally I'd go with the Creative. I think they look great, and I really liked my Inspire 2500s when I had them (with bass set to a quarter).
The only downside to the Creative set is the power/audio in cable being hard-wired to the sub unit. All cables on the 2500s were detachable (from the sub).
Higher-end Logitech systems are quite good too. Have never heard or seen of Hercules or Microlab.
The most important thing: adjustable bass (so you can turn it down to your liking)! I aim for the flattest frequency response possible - the thrill of thumping bass lasts only a few minutes.