Well I have logitech Squeezebox Wireless Speaker System at home, but its not cheap at £250. (It was a freebie, I would never have paid that for a set of pc speakers.)
The best one is Z Cinéma Advanced Surround Sound System from Logitech, but again its not cheap.
You need to think about how much you are going to spend and what you’re going to use them for.
I think the best thing you can do is get a cheap set of usb speakers.