I'm an active listener of internet streams and have both an outboard USB-based soundcard plus the Squeezebox 2. Both of these arrangements give me quite a bit of options. For both, I run them through my Mac C2200/Mac MC-225 monoblocks/JBL 4425 monitors with excellent results including surprisingly good soundstaging.
Firstly, on the soundcard approach, I've found there are *some* good quality internet streams out there - KPLU.org and KCSM.org are 2 that quickly come to mind. Also, I've been impressed with the Swedish Broadcasting Classical channel on their web site, too. Again, depth of the imaging and overall sound quality far surpasses most anything I've found so far.
I'm amazed, though, how many higher bitrate streams do not sound good and I'm convinced that the station engineers just haven't figured it all out yet.
On the SB2, I'm getting good results from the Radioio.com streams. All of these streams are excellent quality and good dynamics. I particurlarly like the Classical, Jazz and the Acoustic streams.
BTW, I also use an Alilent (formerly HP) power supply to run the SB2 instead of the little wall-wart PS they ship with the unit.
Cheers,
David