This is a fairly large topic. Define "media". If you literally mean audio, and that's it, don't buy a computer.
..I now realize I can't remember the name of the thing I'm thinking of
I think they're $200. It will receive MP3, FLAC, and a few other formats via network, and there's a wireless version if you can't run cat5. It has some other neat stuff, like displaying RSS feeds while idle. I'll ask what they're called and append this post..