I've been using Pandora, Slacker Radio, and Last.fm but I think DroidLive Lite is probably my new favorite. It's a Shoutcast client, doesn't require any registration of any sort, and plays hundreds if not thousands of stations from around the world. It seems to be put together pretty well and I haven't found any bugs. Stable app! Anyway, I was impressed that I was able to listen to DigitallyImported (www.di.fm) using this app.
It pairs well with the new Sleep Timer app too so I can listen to music before I fall asleep and have the phone turn the radio off after a set amount of time.
I can't wait to see what this phone can do after a few more months!