The latest iPods seem to have all of the capabilities of a media center. In addition to Apple's Universal iPod dock, some third party companies have come out with some cool docks that have nice interfaces.
The HomeDock Deluxe and the TuneCenter allow you to play your audio, video and photo content on your TV. Each of these presents a interface that is designed for the TV. One feature that the TuneCenter has, is that it will play Internet Radio stations.