I need new speakers for my computer, I know 2 people who have logitech Z-560s at 400 Watts Im looking to beat them in whatever I get.  Any ideas whats good out there?

I dont have a home sound system this will be my only thing to function as stero, I dont watch TV.

Logitech Z680s. 5.1 500Watt sound. capable of decoding Dolby Digital and DTS sound.

i have a pair of bose 901 speakers powered by a onkyo receiver hooked up to my computer

they sound pretty good

i got the whole rig for $300 bucks from a relative because he wanted to "make space"

i'd never buy those overpriced bose speakers new

In the "under" $400 retail pricing (cheaper if you look around) The top three sets of quality "computer" speakers in a "5.1" format are the Logitech Z680, Klipsch Promedia 5.1, and the Cambridge Soundworks MegaWorks 510D.

All of them are THX certified (whoopie) and rated at 500 watts although they also all rate this as a short term continous power output (like 30 seconds worth of continuous 500 watts).

In this <$400 category, the Logitechs have the most features (Dolby and DTS built-in decoding)and is most popular with the gamers (super boomy bass). Pseudo audiophiles tend to go with the Klipschs (mainly the name brand involved), and Creative Audigy people go with the Cambridges.

In the $400+ (nominally around $500 retail)computer speaker category, you have the Klipsch 5.1 Digital Dream Multimedia System which is the same as the normal 5.1 Promedia's with the addition of a preamplifier with:
All Digital Format Decoding: DTS; Dolby Digital 5.1; Dolby Pro-Logic Digital Decoding
5-Band Digital Equalization
Bass management and dynamic compression options
Optical/Coaxial Digital S/P-DIF inputs/ 3 Analog Stereo inputs
Convenient Wireless Remote Control

The other ~$500 dollar set is the Creative/Cambridge Megaworks 650. This is speaker only "6.1" system rated at "600" watts but does not come with a decoder or anything.

With the standard Promedia 5.1, Cambridge Megaworks 510D, or Camridge Megaworks 650, you will "need" a good sound card that supports the Dolby and DTS decoding "and" has outputs supporting the speaker format (5.1 or 6.1).

I personally have the Promedia 5.1's connected to a Creative Audigy. Works great and plenty loud. That being said, I would still rather watch movies on my TV with its' surround sound system than watch it on my 21" monitor and the Promedia's. While it's cool that I can shake the house with music from my computer room if I want to, I tend to do that with my home stereo and not with the computer. Trying to do stuff on the computer and blasting music at 100db right into your face is not enjoyable. Plus, even though they are great speakers, they still don't sound near as good as even mid-range stereo systems. The only time I really crank the sound at my computer is during GAMES, and for that the Logitech 650 4.1 series is just as loud and a better value especially since most games don't support 5.1 sound.

My younger brother bought a set of the 560's and they rock!  I still think it is the biggest bang for the buck.