Pandora was the original internet radio........It has a huge customer following, is supported by various manufacturers, and is the "iPod" of music streaming (iPod as in it was first, and it's here to stay)....If you're on a budget and a decent amount of control over your system, just pick up this:
http://www.crutchfield.com/p_500CDE1...2.html?tp=5684
If you have a 1200 dollar budget, I suggest the Kenwood DNX9980HD.