i hear you there i also have a xbox 360 which has it happen often too
personally i dont think it is so much a console issue as it is a connection issue because it only happens when it is really starting to lag and just imagining a connection that is fragile already then having all the packets from someone ramming into you being crammed down that line could cause it to get jammed and cause a freeze. (I only say this because I have had it happen to me in Commander Mode where the graphics dont change very much lol)
though i have also noticed otherwise that my system really gets hot after only seconds of starting up even when well ventilated and will freeze on first game after starting up my system. (so it may need some kind of external fan blowing on it to help reduce the heat on the system)
though i stick with my first idea because my system still responds if i touch the on/off button instanly where as when it first came out i would have to unplug it because it wouldnt respond to the on/off switch.