looks
My E2180 at stock 2.0ghz plays 1080p MKV files at 20%-50% max

, GPU usage 1%-6%
Media player classic- homecinema used with coreavc codec. (the coreAVC saves about 2%-5% cpu usage

)
With MPC-HC you can make your supporting 2xxx 3xxx 4xxx series to off load cpu usage

, of course the files got to be h264, i follow
this guide and made drop the cpu usage to 10%-30% and upped gpu usage to 14% but when you want to skip it has some delays like a second or two.

for HTPC's its good to get power saving components