Based on your criteria, I assume you want the camra to "do" as little as possible. Of course, you immediately have to decide between SLR and rangefinder.
For SLR, my vote must also go for the Olympus OM-1. It is so much smoother, quieter, smaller, and with a bigger viewfinder, than the otherwise very nice Canon/Nikon "heavy metal" cameras like the F1.
Of course, the OM-3 just builds upon the OM-1 by remaining manual, but by including arguably the best metering system ever put into an SLR.
But for the essence of what you seem to be wanting here, the OM-1 it is. It is, for lack of a better word, svelte. The Canikons are bricks, good as they are. And the Olympus Zuiko lenses are legendary.
For rangefinder, the best is surely the current Leica MP, it is built to unimaginably good standards, but then again, so are most of the M-series cameras. So, excluding the electronic M7, any Leica M is hard to beat. For a rangefinder.
You can buy 10 good OM-1's for the price of one good Leica M, though :-(