I have been playing with Boxee a lot lately and I'm excited about it. Out of the box, without any configuration, there is an absolute ton of free media available to you.

On the plus side, you don't have to run a separate server to handle transcoding. As a result, your files look better and load much quicker.

The downside is you need an AppleTV, Intel Mac, or Ubuntu Linux box. The AppleTV is cheap and quiet, but it also chokes on a lot of HD material over 720p. Mac Mini is appealing for its size, quietness, and bundled features (optical audio), but it's costly compared to the AppleTV. Ubuntu Linux box is probably the cheapest of them all since many of us will have something lying around. The problem is making a PC quiet and having it look like it belongs in your media rack.

I'm actually going to give Boxee a shot on an old P4 2.4GHz machine running Ubuntu Jaunty tonight. Hopefully it goes as smoothly as the Mac installs have gone.