Hi! Just bought a new 5.1 surround system for my PC, and the onboard sound does not do the speakers any justice in terms of sound quality.
I've searched the internet high and low but to no avail when it comes to choosing the best for price/performance. I'm not bothered weather it is PCI/PCI-X, as I have both spare on my motherboard.
As mentioned in the title, it will be used primarily for gaming and watching Blu-Ray films.
I'm personally fed up with Creative's support and wouldn't buy another creative product for a while. I'm hearing good things about HT Omega's product line, though. The Striker isn't much more than some of the low end X-Fi's.
On the other hand, a plain old Audigy SE is probably good enough if you don't want to do anything too fancy than PC Speaker 5.1 in a smallish room. It has very mature drivers because it is so old.
On a side note, if I was really a stickler for sound, I'd decode my audio outside my PC. Those wimpy 3.5 mm jacks just don't cut it for me.
Any card with SPDIF out (optical or coax) should be fine which is almost standard on any sound card more than US$20. I'm surprised your Mobo doesn't have it. I think the Omega HT Striker still might be your best best because of the robust digital out at the price. It even comes with the stupid TOS-Link.