Make that two: Verdana. Both designed by Matthew Carter. You may remember him from the hit film, Helvetica.
The reason are the curly quotes. “They are all weird for English text” (you might still justify the way they look somehow – I guess they are not technically incorrect) and flat out wrong „when you follow the German convention for curly quotes”. (Since HN uses Verdana you can see right here how screwed up those curly quotes are.)
Those quotes should look like 66 (beginning, top) and 99 (end, top) for English text and like 99 (beginning, bottom) and 66 (end, top) for German text.
I guess you could use «guillemets» instead.
It just looks cleaner to me. Curved quotes look good in large size print, but I'm really not a fan in smaller font sizes. Do you have any examples of good quotes in small font sizes?
I do, however, think that as we are moving to higher PPI screens curly quotes do look better (and, as you can see from my German example, some languages require you to put quotes in places where you cannot put straight quotes). I, for example, really don’t think straight quotes look any good in print which is high resolution. In print all the small features of quotes are always clearly identifiable.
I actually think that Georgia has nice curly quotes but they do clump up below 12px or so font sizes. I think no font is free of that problem. I still like to use curly quotes, well, just because. I certainly can understand why you wouldn’t want to use them at small font sizes on the screen.
(There is one exception. I like to use Letter Gothic for my snail mail correspondence. Letter Gothic is a great monospaced typewriter font and to preserve that typewriter vibe I like to use straight quotes.)