Basic blu-ray HTPC: ~$330
The Asus At3IONT-I Intel Atom 330 NVIDIA ION Mini ITX Motherboard includes 2×240 pin memory slots allowing up to a maximum of 4GB of Dual Channel DDR3 1066/800 memory. A built in Audio chipset allowing 6 channels of sound using Realtek ALC887, and 6 x USB 2.0 real panel ports (2 onboard USB 2.0 ports), 1x HDMI port, 1x Optical port, 1 x PCI Express x16 port. This ASUS motherboard also comes with both an Intel Atom 330 Processor, and NVIDIA GeForce 9400M video built in.
In this build I included a GeIL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1066 (PC3 8500) Dual Channel Kit Desktop Memory Model GV34GB1066C7DC, a Western Digital AV 320GB 3.5″ hard drive, a LITE-ON Black 4X Blu-ray Reader SATA Model iHOS104-06 – OEM, and chose the APEX DM-387 Black Steel Micro ATX Media Center / Slim HTPC Computer Case w/ ATX12V Flex 275W Power Supply HTPC computer case.