I used to listen to
my Yahoo radio station, but you have to pay or listen to endless repeating commercials...and they're really bad commercials to boot.
Proton Radio is cool sometimes, but they are hit and miss IMO.
So enter
Pandora. The free version has no commercials and it recomends some really good music. Just enter any band to get started...it's real easy and intuitive. Hope you like it as much as I do.
Supposedly it was started by some Music PHD's.