I tend to try different ones out while I'm at work, since I mostly listen to the albums I've got when I'm at home. So, post some stations you dig, so I can benefit from your impeccable musical taste.
I was down with Soma FM - Indie pop for a little while, but they get repetitive and, well, too poppy. However, another one of Soma's stations, Secret Agent, is pretty good. Plays some great jazz. Both of these can be found at
http://www.somafm.com
Another one that's hit or miss, but mostly good, is
http://www.woxy.com