This socket is our favorite. When AMD released this socket we believed that it was the worst buy. But three years later the first cpu Athlon64 3200+ is still in the market and is not a low end cpu! It is the only socket (during the last decade) that three years later you find lower power cpus in the market than the first released! This means that socket 754 supports capable cpus to run a lot of everyday applications, like those somebody runs on a Htpc. It also supports 64bit so it's sure that tomorrow you will be capable to run the new versions of today's applications.
  We found two low cost motherboards for HTPCs.

I) MICROSTAR MSI K8NM-FISR RETAIL



Form factor: Micro-ATX, 24.5 x 24.5 cm.
CPU: Socket 754.
Supported processors: AMD Athlon 64 / Sempron 32bit(Socket 754).
FSB speed: 800 MHz.
Chipset: nVIDIA nForce3 250 MCP.
Communication Ports: 1 x AGP 8x slot, 3 x PCI slots, 4 x USB 2.0 (4 more can be added externally), 1 x Parallel, 2 x Serial port (COM1 + COM2), 1 x PS/2 Keyboard, 1 x PS/2 Mouse, 1 x Audio I/O (Line-in/Line-out/MIC), 1 x RJ45 LAN Jack, 1 x IEEE1394 (+1 externally).
Hard disk support: 2 x Serial ATA devices - support RAID only on master mode, 4 x Ultra DMA133/100/66 devices.
RAM Sockets: DDR memory architecture 2 x 184-pin DDR DIMM socket support up to 2 GB, DDR400/ 333/ 266 DDR SDRAM DIMM.
Additional characteristics: onboard 6 channels software audio codec Realtek ALC655, onboard LAN Realtek 8110S 10/100/1000.
BIOS: 4Mb Award BIOS with PnP, ACPI, SMBIOS 2.3, Green and Boot Block, Provides DMI2.0, WfM2.0, WOF, WOR, chassis intrusion, and SMBus for system management.


II) JETWAY K8M8MS



Form factor: MicroATX 24.4cm X 21cm.
CPU: Socket 754.
Supported processors: AMD Athlon64.
FSB speed: 800 MHz.
Chipset:
- North Bridge: VIA K8M800
- South Bridge: VIA VT8237
Communication Ports: 3 32-bit PCI Bus Master, 1 AGP 8x, 8 X USB 2.0, 1 X Serial, 1 X Parallel, 1 X PS2 Mouse, 1 X Keyboard, 1 X Line in/Line out/ Microphone, 1 VGA.
Hard disk support:2 x IDE up to 4 IDE devices, 2 Serial ATA Ports with RAID0, RAID1, RAID0+1.
RAM sockets: 2 x 184-pin DDR Module Socket for DDR266/DDR333/ DDR400 up to 2GB.
Additional characteristics: onboard 6-Channel CODEC Compliant to AC97, Realtek 8100S 10/100 Ethernet, vga with 16-64Mb shared memory from RAM (RAMDAC 300MHz and resolution up to 1920 x 1440).
BIOS: Award BIOS , Support Green function, Plug and Play Function, 2MBit Flash ROM.
  These motherboards are cheaper that those we found for P4 LGA 775 socket. They cost about 60 euros. But P4 motherboards have better vga chips onboard. It seems that ATI Radeon Xpress 200 chipset is a very low cost solution. Although we remind you that Athlon64 and Sempron consume less power so they are recommended for low noise Htpcs.