the newest mini-itx 1ghz can do divx and dvd playback fine, and should be able to emulate 16bit consoles fine, but anything higher requires more horsepower and a much better gfx card. some of the newer mini-itxs have built in mpeg2 decoding and tv-out i believe so dvd's are no problem. They are designed to be silent media boxen. more info at
www.mini-itx.com