All that comes to my mind is: High Temperature Personal Crashers.... So this's ad's highly dangerous forum part or what?
HTPC == normally a custom-built mini-sized PC with TV out, DVD-ROM drive, reception panel for remote control and running some customized version of Linux or Windows Media Center as an OS. One of the main terms you're looking at is Mini-ITX -- a mini-sized motherboard, usually made by Via. But it can be your beige PC with TV out, carried to your living room, but we don't focus on those boxes here.
My personal opinion (lol)....its easier to buy yourself a good 6.1 THX amp (marantz lol), some good quality Monitor Audio Floor Speakers, a good DVD Player that does everything, and a nice Projector and screen. That way you really have whats called home theatre.
Oriphus: Sorta true, but some Linux VDR systems when bundled with DVD-R drive and DVB-S access, provide quite amazing things in one box <i>(Tivo type of VDR system added with possibility to burn DVDRs, watch DVDRs, etc)</i>. Sure, I prefer myself the "easy way" as well and simply love my Pioneer 444 + stuff, but this "media center" or "HTPC" concept has very much potential in it.
I`m using All in Wonder 8500 128 for my grapics display, sound Blaster Audigy 2 pla1tium, sourround sound 6.1 with powered sub-woofer also by creative. Actually designed for the sound card. Ath XP 2400 w/ 1GB of DDR333. Also have a Creative dvd-rom & HP dvd200i writer w/record now. I like it . fills the room 20X18 w/ rich sound.