Wanted: good player for playing 7.1 surround sound video files. It should indicate if the source is 5.1, 6.1, or 7.1. It should tell you if it is unable to playback correctly.
VLC: Free. Sometimes m2ts files are silent on the primary LR or center channels. Not even sure it can decode 7.1 dts. Nice ability to select audio source and audio device however.
Boxee: Not tried. Does it work? New beta seems good.
XBOX media center. This is open source so I am assuming it doesn't work with stuff you can buy in a store. Am I wrong?
Free MPC: free, comes with some good k-lite codec tools, including one that let's you select # of speakers in your system. Invisible controls. No way to setup since it is a hodgepodge.
Non-free software: Ok obviously I need to buy this. Right? What do I buy? What are you guys using to play m2ts mkv files with a variety of audio channels. stereo, 5.1., 7.1, dd, etc.