I agree with Enders, but variety is the spice of life, so I'll throw this out there: I prefer MPC-HC (properly set up, of course), because XBMC is too much of a GUI (almost an OS) to me. Don't get me wrong, it's highly functional. But I prefer to just open windows explorer and double click the file I want to play. Good thread here on how to set up MPC-HC: http://www.avsforum.com/t/1357375/advanced-mpc-hc-setup-guide
So you would primarily use them to stream movies from your pc?