The Squeezebox looks like a very cool device. It plays MP3, WMA, AAC, Apple Lossless, Ogg Vorbis, FLAC or uncompressed audio on your home stereo. It has a LCD display to display the menu for selecting songs, as well as the currently playing track. There is a 802.11 wireless version and there is a ethernet version.
One of the best things about this, compared to the other devices of this type, is that the server is open source. There is quite a lot of development on this. Also this sever can be used for streaming to a computer.
It looks like the wired version starts at $199