OS X objectively has the absolute worst font rendering. It does not use hinting at all and relies only on grayscale anti-aliasing.
And yet OS X's font rendering being by far the best for me is a key thing that has kept me on the Mac despite all the other warts. I find text elsewhere horribly blocky. It's all very subjective, it seems. Also, I think the grayscale antialiasing is a new thing, it certainly didn't used to be the case, but maybe they switched how it worked once retina screens became the norm.
And yet OS X's font rendering being by far the best for me is a key thing that has kept me on the Mac despite all the other warts. I find text elsewhere horribly blocky. It's all very subjective, it seems. Also, I think the grayscale antialiasing is a new thing, it certainly didn't used to be the case, but maybe they switched how it worked once retina screens became the norm.