I am designing an HTPC. I already have all the other parts down. If you guys want to know what parts I'm putting in it and what cool case I am using, let me know.  
 
Anyways I've read forums about debates between sound cards and I'm still not too sure. I've heard of the LynxTwo or something like that, Audigy2zs Platinum which i have myself for decent music quality, X-fi line, and turtle/auzentech.  
 
Still wondering what to pick. Dont want to spend too much on audio just decent to decode/play HD streams or whatever.  
 
As for speakers, i dunno. z5500? a 7.1? Home theatre speakers?
 
 
Also i forgot to add in the Razer AC1 barracuda, heard that one was awesome too.

Either of these would be good.  I have the Omega HT and it's terrific for music.  Both get very good reviews. There is an Auzentech that uses the same chipset but not sure of the model.  Currently running my sound card through a receive so no speaker suggestions
http://www.newegg.com/product/prod [...] 6829127002
http://www.newegg.com/product/prod [...] 6829271002

i've heard about auzentech. dont quote me on this but i've heard the chipset has bad support

but how would u compare this to the x-fi? I'm only bringing up the x-fi cuz it has so many ports and such. very accessible to noobie users

The above 2 cards with links, as well as one or more of the Auzenteck are using the C-Media CMI8788, which was first designed for audio/video and secondarily for games not that you can't use them for games.  The x-fi series is designed first for games os for HTPC the C Media would make more sense.  While a bit pricey the Omega HT has been terrific and the bluegear has gotten very good reviews
 
http://www.elitebastards.com/cms/i [...] &Itemid=27

ooo. thanks for that info.

 
 
LynxTwo is pro sound card and not design for Hometheater PC application. Call Lynxstudio if they will even support you for your application or even support for the DTS and all other digital sound format or configuration.
 
However I read a review about the other soundcard mentioned and it turns out that the Azuntec is better on using for Home Theater PC application than Sound Blaster cards especially the Auzen X-Plosion. Unfortunately I couldn't remember the review site.
 
g-paw link about the X-Meridian has MCE support so...

Right now I'm using Souund Blaster Audigy ZS2 and ATI x800 pro with TV Wonder HD 650 on a pentium 4 2.0 GHz and it's all working fine. and for the Video Card I replace the fan with fanless heatsink thermalright HR-03a.  
 
Windows Vista Ultimate have MCE built in on the OS you can use that OS too. I didn't try any other Vista version so I can't tell about the other ones. If you go with vista get the HD 2400 is supported or somewhere along that line of a card from Nvidea.  
 
The ZS2 is also supported by MCE because you can (and make sure you) download the updates from Microsoft for XP Media Center Edition 2005 (MCE).