> [...] part of me gets really giddy when I discover a site with very little styling.
You can set your preferred font families in your browser's settings that would be used exactly in case of "no page author font preference".
(You can even tweak default sizes, and even default colours, but setting wildly unusual default colours just reveals flaws in most author styles, so are not very practical, unfortunately.)
It is quite widely known fact (I think) but probably very rarely used feature; sorry for 'mansplaining' -- I bet you all know this and I would not be surprised if some of fellow HN readers even have non-default settings in there.
> I usually prefer Georgia [...]
What a coincidence, I read HN (and Wikipedia) in Georgia font, but not because of default browser settings, but because of site-specific user styles. I like my browser to be real "user agent".