Ah, to hear even a mediocre system in a great room would change many minds here. The room is without question, to my mind and experience the single most important factor in good sound. It will expose both weaknesses and strenghs of a system, as noted above, to a greater degree than any component. Speakers and amp interface are equal, pre-amp sends the small signal to the amp/speaker and is second to the room.
The source is very important in that it can really improve dramatically the system performance beyond getting the room, pre-amp, speaker/amp right. A great source component in a system that is flawed downstream is not going to make a disernable difference.
I believe it so much that I am in the process of finally carrying out what I believe to be true, designing and building a dedicated room. It seems at this point to be the best investment I can make in improving what I currently have which in my estimation isn't even close to being realized.