In answer to FallisPhoto, perhaps another way to ask this question is as follows ...
Assuming that you are out with a camera that was given to you, and had only that one, and you were to be asked which of the parts I've chosen in the list (including whatever film HAPPENED to be in it) would you sacrifice the quality/usability of LAST, in order to acheive what YOU want photographically?
For example, is the lens that happened to be on that camera at that time the most important to your objectives, i.e. sharpness, contrast, later enlargability etc.? Or is it the specific type of film you use that could possibly define your work more than anything else, like say Tri-X? Or is it the usability of the viewfinder (assuming of course the camera has one in the first place!) that is the one over-riding thing that must be right FIRST in order to facilitate your photographic objectives and allow you to work the way you do in that regard?
Yes, you could list a whole lot of other things like the shutter in a camera etc. because it is obviously a part of the camera too, but I wanted to stick here with what I think are the three most obvious ones that - depending on their type/standard etc. - are the very things that facilitate both your vision and the characteristics of your end result, for YOU as a photographer, personally. I don't mean to open up issues regarding whether the film, or the lens or whatever else, can be deemed a part of the camera or not.
I put the last 'name on it' option there both as a bit of humour and for the fact that there are people I know that will ONLY EVER shoot with a specific brand, perhaps for psychological reasons. Therefore, they can't BE photographers at all without their beloved 'Nikon', 'Leica' etc, because perhaps they cannot be 'in the(ir) zone', so to speak, while they are shooting unless they KNOW IN THEIR MINDS FIRST that it's a 'Nikon' or whatever in their hands.
I think it's just a very nice simple question and an important one as it helps me to very efficiently shortlist some possible cameras I might plan on acquiring and using in the future. And I was curious to see what proportion of people (ballpark figure is fine for me) might be of the same mind in terms of their camera's viewfinder usability being the most important thing on their camera that allows them to acheive their photographic objectives more than anything else.