We've actually discussed sound cards and their role's in HTPC's
here.
Basically, if your using it for Gaming and doing digital out, get a card that does Dolby Digital Live encoding.
If you're using it just to play Media (DVDs, MP3s, HTPC sorta stuff) and using digital out, it really doesn't matter what sound card you use, since you're be bypassing the DSP and DAC 99% of the time anyways.
