Windows 7 WMC Streaming Radio
If you're using Windows 7 WMC (or Windows Vista VMC) and have any interest in streaming radio or local radio, then you should definitelly check out the RadioTime plugin. I've previously recommended mcShoutCast or Yougle, both of which can stream ShoutCast stations (Yougle can do more, including YouTube, MSN, etc). I've just come across RadioTime however, which blows them both out of the water.
The WMC/VMC plugin has a very nice interface that's very easy to browse and categorises stations by genre, region & favorites. It also lets you listen to local FM radio if you have a compatible FM tuner (most analog TV tuners will double as a radio tuner).
You can also go to www.radiotime.com and listen to streaming music directly straight from the browser (nothing new there, you can do the same with ShoutCast and many others). The online page also lists local radio stations which are streamed over the internet.