Ok this will be a good thread.

Speakers are the most important because they come first for me when building a system. I don't know the power requirements of the amp until the speakers are chosen. The source can be chosen first, but it has no limitation of working within a system like the speaker and amp combination. A particular source will work with any speaker/amp. A preamp may or may not be needed depending on the source or if an integrated amp is possible. Since all the choices can be based on subjective preference, it seems the answer comes down to other non-subjective parameters. The primary one that comes to mind is the wattage requirement of the speakers.
That is not to say I chose my speakers based on their wattage requirement. Room is a good answer too because not all speakers will work in all rooms.

Twl's controlled environment comparison of turntables and speakers leaves me wondering if there was a good match of the Linn TT/cartridge with the Naim and poor match with the Rega.

Was the Rega TT with the Goldring cartridge and the Naim gear the typical combination you used in that store for demos? What were the customers shopping for who heard the comparison and what did they buy?

Twl, I thought the comparison was really thought provoking and convincing in many ways. My post was not intended to suggest you were trying to trick anyone. If you had used the same cartridge I would not question the choice of cables, phono section maybe ;) Did the righteous indignation help close deals with the customers who might have had similar questions? :)

Twl,your posts have caused a renewed interest in vinyl for me.
Thanks for taking the time to share from your experience. Since I have only used digital front ends in my current system, I'm curious if anyone has done a similar comparison of highend digital with good speakers and entry level digital with great speakers.

The initial question or questions are somewhat ambiguous for me. Not because the question marks are missing, but you can take the first two sentences two ways.
1."What....is most important..."
2. "OR what has the biggest impact...."
"OR" can mean "instead of" or "more specifically".
3.Further down seems to clarify the previous questions, "....JUST what do you feel is most important.(?)" indicates the question may be looking for a single component.
4."...but keep it to one part..." seems unambiguous.

Sometimes the intended meaning of a post is misunderstood for any number of reasons in this type of forum and it's often because the post is not read thoroughly. Even that does not guarantee you will understand the intent of the original post.

Uh Uh Unclejeff..this IS Audiogon :)