Anything related to hardware (CPU/MoBo/Video/FSB/BIOS, etc.), hardware settings, overclocking, cooling, cool cases, case mods, hardware mods, post pics of your unique creations here.
Intel's 865G chipset is the bottom-of-the-line option, and is therefore slow. Go for something with an 875P or 915P chipset, or at least an 865PE. SATA RAID and FireWire are both good things to have, and integrated high-quality 5.1 stereo is worth the cash.
If I were you, I would go with an ASUS, Gigabyte, ABIT, or DFI motherboard. Chances are, it would run slightly faster than an Intel motherboard, have slightly better sound, and be slightly cheaper as well. Besides, you'll probbably want to overclock sooner or later.
Also-have you ever considered an AMD processor? The pentiums are admittedly a shade better than the XP line, but they're much more expensive, and the A64 kicks their puny behind.
If you think the P4 is crazy, the Mobile Barton 2500+ can reach 2.6 Ghz ON AIR. That's a 50% increase in speed!
Of course, for a home theater setup, the HT might give you an edge, so it's your call on what to get.