I would think of a mac mini also. Depends on if you plan on streaming stuff. There a lot of ways to do this. If you have a 360 you can stream your stuff to your 360. However mac mini doesn't have HDMI so you would have to think about that. Using OSX is much more stable. The other option is to build a small linux box. But at that point it comes to hardware because you want something quiet. Or the last option is to get a network harddrive and server stuff over the network using mac mini. I wouldn't use APPLE TV because you get locked into the itunes thing. Building a PC is too much work unless you think it's fun and nerdy which i agree it could be fun. But if you're going all the way to building something, linux and open source would be fun. Or even better put OSX on x86.