Rate these on order of importance:

Any of these, plus amplification/preamplification can screw up the sound. If the system sounds bad, the only thing that is important is how you can fix it. Whatever is making YOUR system sound like crap is number 1 in importance and in every system sounding like crap (or to be more P.C., unsatisfactory) that is something different. So, I am not a fan of ranking the importance of equipment in a sound system or cost allocation in a system. The right amount to spend on a piece of equipment is exactly enough to achieve your sonic goals for the system and not a cent more! There are many paths to a great-sounding system and many paths are not super-expensive. Equipment matching and speaker placement are everything. The toughest trick, I think, is going to a stereo store, listening to a particular component in the store's demo system, isolating and assessing that particular component's sonic quality and its sonic qualities from the rest of the demo system and then determining whether and how those qualities will complement your existing system at home while not making a mistake in judgement!

Is it safe to assume that many people (incorrectly) choose speakers as the most important because they are the most flawed piece of gear in the system?

Why would people choose as most important a piece that has least to do with the reproduction of the original signal?

Do speakers retreive the signal from the source? Do the transmit it to the pre-amp? Do they process the signal and output it to the amp? Do they amplify it so it is loud enough to be heard? Do they transmit the signal from the amp to the binding posts?

So they have no effect on the signal until it arrives at the cabinet. How can they be more important than anything ahead of them?

c'mON Nrchy, nothing has any effect on the signal until it arrives at it! An amp has no effect until the signal arrives at it. How can that make the amps more important than any other part? What type of logic is that?

Nrchy, we've been down this path before. While speakers can't improve the signal it recieves (digital correction excluded) they are the most likely culprit to intertwine with a room in such a way to distort it more than any other resonably performing component. And by the same logic no component can improve what was put on the recorded medium (equalization(?) & digital correction excluded) to begin with. There seems to be more consistantcy of performance amongst other like components than speakers. You may disagee with the opinons of others, but, that alone doesn't make them "incorrect".

The point is that if the signal can be transfered to the speakers with a fair degree of accuracy that the speakers will have something of quality with which to work.

Garbage in Garbage out! If the signal is so corrupted when it arrives at the speakers, it doesn't matter how good the speakers are, it will not sound good, or should I say correct?!?