As someone who thinks the best beard is no beard, I expect our rankings by this criteria will be incommensurable (and I say that as someone who named his philosophy Commensurablism).

I think Karl Marx really pulls it off.

If a mustache connects to a beard, does it share its being with the beard?

You might have to block out mustaches depending on how you want to do the judging.

In fact, will have to block out the philosopher entirely and just see the beard, to be anally objective.

Those ranking philosophers! I was once near one, and the rank smell almost knocked me out.

Continental philosophers generally take less frequent baths than their American Analyitic counterparts.

And females hardly ever enter the profession for this very reason.

Physical over-cleanliness and fifi and boobie and primness and such have never been part of my life.

Loftiness is much more apt to stick to a philosopher than cleanliness.