I've been using wunder radio for several months, but I frequently experience a station stopping or not starting. Altho it has a limited station selection, I've found aol radio to be much more stable and reliable.
My solution is streaming the radio stations wirelessly from my PC to my iPod Touch using TVersity. I can pretty much pick ANY stations that I want from the Internet. I'm not bound to any particular app. If Windows Media Player can play it, so can my iPod. It's not limited to just audio either. You can stream video as well. However, it needs to transcode the video into MP4 first before streaming it to the iPod due to Safari's shortcomings of video streams. (Thanks again Apple. hehe)