I had to read this as I thought the final word was 'impotence', which would definitely change the question a bit. I think hearing is the most importantr thing to us as it allows us to communicate by being able to listen to others, but I'm sure there isn't any single point of view on this one.
The brain would be my answer as well. Science and religion both are beginning to focus more and more to the healing power of our brains and the potential that it holds to regenerate cells under the right conditions.
It depends on what I'm doing at the time. When I'm hungry, my mouth is most important. When I'm learning something new, it would be my brain. When I'm out for a run, definitely my legs are top of the list. Does that mean I'm fickle?
The most important part of the human body is the brain. Without it we can not use your consciousness or conscience.
The eyes are the second- because visual ability can read things which cannot be heard via ears.
The heart runs close to second, but for this example or context, it has to be third- because it gives us the ability to feel and love, breathe(your heart is essential to your existence, should it stop beating, then your brain will suffer).
You can live without smelling. You can live without walking or running. You can live without eating(because you can eat via tubes, if necessary). You can also live without hearing.
So, I guess it boils down to an individual's own understanding of life.
Is it the most important part or how it's being used (no I'm not only referring to that :-)) Perfect eyes that look away at first glance, the most beautiful hands that feel like jelly...
I don't have a lot of insight in good looking guys but I do know woman who objectively speaking are average, but because their body tells a story of.. (your personal dream) ... they look absolutely gorgeous.
In spite of this economic crisis it has become neccessary for most to 'cut back' on non-essentials, myself included. I have come to realize that getting a manicure/pedicure and salon appointments (to get my hair washed...