I would go for one of the newer graphics cards with onboard HD decoding on it like the Nvidia 8600 - if you don't need gaming that 8600 offers great value for money. (note that this is better than some of the 8800 series cards as it has a better decoder on it). On mine playing a HD-DVD or BluRay only using 5-10% CPU because its all offloaded onto the 8500 GFX Chip

For CPU I would go for something half decent. Last night I tried playing a rip from a Sky - 1080i h264 footage and it was maxing out my Dual Core 2Ghz CPU ( well 1.6Ghz overclocked - unfortunately this won't offload onto the GFX at the moment as its not supported) Something like a

Intel Core 2 Duo E6550 2.33GHz
or
Intel Core 2 Duo E8200 2.66GHz

would do the job really well without breaking the bank.

i would be connecting it to my 32" tv in the lounge running 5.1 etc and it would be for hddvd and would want to use it for normal pc use also but thats not a priority its only an idea for now jus wanted some advise on what would be the best to get not really got a budget as of yet as i have no idea what i would need and what it all costs

With RAM prices as they are I would say 2GB, CPU wise, one for around £50ish should be good enough.

Graphics cards is where it can get interesting. What are you connecting up to.

Soundcards - Again - What are you connecting up to do you want optical? analog? 7.1, 5.1 etc

What sort of stuff are you going to be playing - x264 rips - BluRay / HD-DVD etc?

http://www.bit-tech.net/hardware/2008/02/05/home_theatre_pc_motherboards_feb_08/1

tbh, you dont need anything too special for a media pc.
Id say a gig of ram and a reasonable CPU.

The only thing you need to consider is storage. I personally use a NAS to store files on the network.

What you wanting it for? What sort of budget? What sort of size? Whats it going to be linked to? blah, blah.

dell?? saves the hassle!

U2U barnshaw, he knows absolutley everything about making the best HTPC, helpful guy!

If he's got a 360 (I'm guessing, based on him having an Xbox Live tag), then he's already got a Media Centre Extender.

Get a media centre extender. You don't need a whole PC dedicated just to stream movies to your TV :)

I recommend scan, i recently built a new rig, bought everything there and got great prices on everything and greast custommer service(delivering on time etc).

can someone give me some advise on what would me needed and where to get it from doesnt have to be anything massively spec`d jus something half decent