What is most important part of a system?

all true, but the real issue is where to spend the most money

that is the way this question is usually interpreted anyway

with digital, that means the only transducer left is the speaker (and as per above, its interface to the room)

if its a case of where to spend the most money, in this audiophile life we have never usually really got enough money so my go at answering this question is now going to be speakers, having great speakers at least makes sure that you have left the best till last and whatever signal has been achieved by your system it will not be getting held back at the last part of the chain, garbage in garbage out will still be playing a big part here but at least the speakers will be as good as you can get , no good spending most of your money on a piece of equipment further up the chain if you have got a pair of s**t speakers  , so on a budget the new answer is definitely spend the most money on the speakers , room acoustics are a big issue but very simple free ideas like hanging curtains around the walls and adding some soft furnishings like rugs and cushions usually can tame a lively room , using simple 40gbp RDC cones under your speakers is a good prity cheap solution , so where to spend the most money will be speakers definitely. 

randy-11I am not likely to let big kidz anywhere near my system.  I like this!

czarivey If there's a $35k budget for DAC, why not try $250 DAC and see what changes positive or negative rite?

I have been repairing, building, modifying components for 25 years.  Built almost everything out there, tired caps, resistors, tubes, cables, etc.  I am lucky to be in an area where I can hear many many systems and components, also when repairing something, I can hear it in my system.  It cost over $3K in parts for my DAC, why because having a partner who is has a masters in EE, we can build anything we want and that is what it takes to make our DAC.  If I could build something cheaper that sounded as god as my DAC, boy I sure would!  I could send the design to China, send it to dealers and retire.  When I bring my DAC over to someones home to hear in their system, it takes 30 seconds before they say, i want one, they tell me that they have been audio people for 20-30-40 years and have owned many components, then they ask how we did it.  I am not saying that I am the only one who can do this but I am one of the few who understands how to make a Direct Heated Triode DAC and preamp (no caps in the signal path).  Recently I had a gentlemen who worked in the industry for 35 years, retired now.  He has seen everything in his system and most people who compared theirs to his, never made it.  When he heard my DAC in his system he bent down on one knee and ordered one.  30 seconds is all it took.  It took a few years to make this sound the way it does.  Send me the DAC you have and and I will set up a meeting to compare the two so it won't be just my opinion.  I will make an exception and do this.  It will be fun for 30 seconds!

Happy Listening.      

It will be fun for 30 seconds!

Why does it take so long?
If the difference is so big I usually don`t need more than a couple seconds to pick the winner. :))

Plutos  Most people are not prepared to hear the difference.  They kind of get a puzzled look on their face and then move to sit in the position where they normally go to listen, pull out a recording they want to hear and then they ask how much for me.  I wanted to give the benefit of a doubt also.

But I like your thought process.