Thanks, Unsound!
Though I'm in the "amp first" camp in this thread, I still feel the source is definitely important. In fact, critically important.
One trend this type of argument (more commonly: speakers or source) often follows is to dismiss the importance of the other side of the argument altogether. Most of the audiophiles whose opinions I respect would never go down that road.
A personal anecdote, five or so years ago, one of my local dealers hosted a gentleman from Linn at his store on a beautiful autumn Sunday afternoon. Obviously, you know where Linn's opinion lies.
The system this fellow demonstrated for us featured their $20K CD player on one end and a lower end (something in the $1100 - $1500 range, though I've respected their micromonitors that have long slotted below whatever this model was, pricewise) Linn speaker on the other. The Linn amplification used fell somewhere in between those two extremes. He made the usual statement about the source being everything, and to prove it, you could basically use "any old speaker" as a speaker can only reproduce what is passed to it.
The overall goal was to show how divine the result would be in having one follow the Linn philosophy, and spend a disproportionate share of the system budget on the source
Needless to say, the sonic experience of the system was far less ideal than we were being told. Apart from hopefully providing valuable insight into how wrongheaded the Linn approach actually is, I found the entire exercise ridiculous. For the sake of argument, I'll put a $30K price tag on the system, and believe that if I were allowed to divvy that up into 4 $7500 portions, then go around the store and grab a CD player, preamp, power amp, and pair of speakers that individually came in at or less than that $7500, the end result would have walked away from the system that was demonstrated.
My overall point, to quote Kondo-san of Audio Note, "Nothing is unimportant."