I intentionally excluded Adobe Source and Roboto, because they lack italics in some families; and GNU Free and Liberation, because they aren’t proper super-families, rather free alternatives to Microsoft’s old “web safe” fonts.

Added Adobe Source, since it now has italics for each family.

Hey, what about Alegreya? To me, it's the best free superfamily of all -- there's serif and sans serif, with proper bold, italic and small caps for both. The letterforms are beautiful, especially the serif at large sizes. I've been using them to design a series of posters at work & I've transitioned to using it on our website, catalog and to save on page-view charges. And yet, I've NEVER felt like I'd compromised. 

And our CEO loves me for it too.... 🙂

Strangely Alegreya is entered under  sans and serif. 

37 minutes ago, Greg Yerbury said:

Strangely Alegreya is entered under  sans and serif. 

I guess not strange since Alegreya has both. But it is a super superfamily, as good as any paid one.

Background: I redesigned our website when our new cost-cutting CEO decided to move our design department from Adobe to free alternatives. So I had to move our website from Mrs/ Mr Eaves. Keeping with the cost-cutting approach, I tried many fonts, settling on Alegreya. At first, I thought I'd be giving up a lot, but I was shocked when I realized I PREFERRED to free font to the well-regarded paid one.

As an FYI, I also tried Source, PT and Merriweather and found them okay, but less versatile. I more or less agree with the writer's grades.

What I meant instead of it being listed once under super family it got two separate mentions. 

4 hours ago, _De_Leon_ said:

Hey, what about Alegreya?

Just an oversight. But you should be able to add it yourself if you think it needs to be listed.

1 hour ago, Greg Yerbury said:

instead of it being listed once under super family it got two separate mentions.

A number of families in this list are already listed in either one or both “best of” lists of serif or sans serif free typeface families.