IMHO JRiver is the best thing since sliced bread for the HTPC crowd! I actually use my HTPC as a prepro - no receiver or commercial prepro in my system. I don't use onboard graphics or audio. I'm using a humble GT 730 for video and a Essence ST/H6 for audio ...I also have Burson opamp upgrades. I perform all room correction (PEQ, FIR filters etc.), bass management, you name it, from JRiver DSP Studio via vst's. My PC outputs to a Adcom 5503 (purchased form one of the Forum founders if I'm not mistaken), 2 Yamaha MX-830's, and a Behringer EP 4000. Those are connected to Klipsch Cornwalls and a Heresy, Definitive Technology bipolar rear and back speakers, and the EP4000 drives a pair of SVS 16-46's and a pair of Wharfedale SW-380's that have their amps and crossovers disabled.
@Marauder1957 You could even get rid of your Carver C-9 Sonic Hologram by using the MSED vst from Voxengo... I did