Most Important?

My opinion is that if you skrimp on the preamp your system will suffer. I would rather have a system with 500 dollar speakers and a 5000 dollar preamp than the opposite.

Wow - what an insane thread. Some of the polarizeed views suggest that Bose and Noel Lee has been extremely succesful at marketing their cheap speakers and expensive cables.

Anyone who thinks that any old speaker will do clearly does not understand the relative difference in distortion levels between electronics and speakers. I know the math can be daunting for some but fwiw we are talking factors of over a thousand times worse for good speakers and hundreds of thousands of times worse for an el cheapo Bose or its equivalent speaker.

Headphones anyone? (for $500 you can get a decent pair)

I have 4 systems, and in all of my mixing and matching etc, I have found that source and electronics are more important.

One of my 1st heavily front ended systems was a Linn Lp12/Ittok/black koetsu/Mitch Cotter step up into a NAD 3020 into a pair of ADS 320 bookshelf speakers.
Total cost of that system was around 3700, with around 3k of it in the front end.
The sound was amazingly good and fun to listen to.

I would focus first on the proper amp, or integrated amp to drive my speakers. Now that doesn't mean that I'm spending more money on the amp than the source, but the amp/speaker interface is very important. A really great amp may or may not be very expensive, it all depends on how it interacts with your speakers.

A premium source is also a high priority. The real key is balance. A great source with a cheap reciever will not get you any better sound than a cheap source with a great amp.
Sorry, there is no real answer, only you can determine what works for you.

Following Tvad's example, right now my money (MSRP) is in:

1) Analog Source (table/arm/cartridge)
2) Speakers
3) Integrated amp
4) Digital source
5) Various tweaks, rack and isolation devices
6) Power conditioning/dedicated lines
7) Power cords
8) Speaker cables
9) Interconnects

Cheers,
John