I actually hate the one on the right. I don't want my favicons to be necessarily readable, or a blur of colors like that.. they're ICONS. Visual REPRESENTATIONS. Infact, most of the 'better' versions on that page sucked a lot more to my eyes.
The ones on the right appear as a blur of color.
Anti-aliased fonts always, similarly, look color-smudged to me, so I make sure to turn off that "feature" completely, whenever I can.
I suspect that, unlike some replies have implied, this isn't a defect in visual acuity (which could be the case, since the one eye I didn't bother to have laser surgery on is far from normally shaped), but, rather, an increase in sensor resolution. Might we have more cones? Perhaps our cones are distributed differently? Do we saccade [if you'll pardon the verbing] at a different frequency and/or to a different extent?
If my dominant eye can focus the image (unassisted now, with spectacles pre-surgery), I tend to prefer smaller font sizes, even on a tight pitch like a 17" 1920x1200. I still wish Apple would come out with a 15" laptop with 1200 vertical pixels.