Built for Pentium “M”s, the AOpen i915GMm-HFS microATX that Hardware Zone reviews is a great starting place for an HTPC.  With built in audio, a 16x PCIe slot, DDR2 support and SATA with RAID capabilites, you can even get some good gaming out of it.
“Not just another desktop Pentium M motherboard, the AOpen i915GMm-HFS is a cleverly designed motherboard specifically targeted at those who are looking to get on the media center PC craze. Check out why this micro-ATX board sits in a niche of its own.”

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