I didn't vote, the format is kind of wrong for my personal opinion (and the basis for my system building).
It all starts at the beginning, and goes toward the end, in that order.
In other words, the source is most important ... anything lost here (compromised, because we are not made of money and therefore have to accept compromise at every step) can never be recovered.
A lot of beginner and intermediate audiophiles do it the opposite ... speakers are most important, then power, then source. Don't worry ... everyone starts out that way, some never change. That's OK; it's your system, your money, and whatever you like is what you like.
But in the end, a good quality source will always produce a system with good overall fidelity, will reveal shortcomings in whatever components that follow (very important for system building) and broadly speaking will last much longer in a system before being surpassed and identified as the "weak link". It generally will resale well and more often than not, you will decide not to sell it at all, and end up in a second system or handed down to someone you know will appreciate it, because for a given outlay, it can't be replaced with a similar Sound Quality (SQ) unit.
The downside is it's hard to do it this way. It's always more exciting, for a while, to buy impressive speakers or more power, and let's be honest ... it won't result in a "bad sounding" system if you do it that way. The problem reveals itself later ... once you account for depreciation and improvements in the state of the art (which means, basically, "how good we know how to make things today") it's the more expensive path to what will eventually become the system you are totally happy with (okay, maybe totally satisfied with ... basically a point where if you don't spend any more money on the system, it still rocks your world).