Ask Engadget HD: Best HTPC to replace my NAS?

Just a few weeks ago, we considered combo NAS / media streaming set-top boxes, but what about those like our friend Matthew, looking for a HTPC that can function by itself as a NAS server without the extra hardware cluttering one's entertainment space? It's all too easy to have a "too many boxes under the TV" problem, maybe you can help him solve this one:

"I'm looking for some advice on an HTPC setup for my home. Currently I have way too many boxes under my television and I'm trying to consolidate them to minimize clutter. One such box is my beloved FreeNAS server; it functions as NAS, a bit torrent client, and has time machine support for my laptop. Is there an HTPC available that might also function as a NAS server with all of the features I use on my FreeNAS server? I also have an Xbox 360 and have considered getting a Windows Home Media Server and using the Xbox as an extender to get the content on my television, but I like the idea of an HTPC with an internal Blu-Ray drive. Do you have any suggestions?"

So what's the best setup to get all that functionality in a single box? Let us know if any of the HTPC builders out there have a solution that fits, or if a custom build (we have a few suggestions to get you started) is in order.