Not strictly speaking an "LFS Rig"...
Last year I set up an HTPC / Home Server build using an HP Microserver, running Windows 7 and DriveBender to pool all my hard drives.
Unfortunately, DriveBender wasn't as stable as I hoped, and the CPU on the Microserver (only a little dual core Turion) wasn't realy ideal either.
With this in mind, I planned on building a new PC to replace it (still using DriveBender) but things didn't quite go to plan.
Ended up with 2 PC's...
Microserver:
8GB RAM,
5x4TB drives (14TB usable in RAID-Z1),
FreeNAS,
Ghetto PSU as the standard one is very noisy,
Intel NIC.
HTPC / Server:
Xeon L5638 hex-core CPU (60w TDP!),
8GB RAM,
Intel motherboard (DX58OG - not bad actually),
Xonar DX,
Intel NIC,
CCL Corsair 200R (CCL version comes with a terrible CCL logo replacing the Corsair one - avoid!),
OCZ Vertex 2 128GB SSD.
Connects up to a 50" Panasonic TV / Logitech Z5500 speakers (not great for home cinema stuff - but they were cheap).
I've put these in a converted cabinet under the TV - lined with some sound-absorbent carpet underlay with a couple of fans installed in the back.
All I need next is to upgrade both boxes to 16GB RAM (FreeNAS *eats* RAM), and maybe I could get a life