Inviting commentary on this.
I found a list of top 100 NGOs, and I checked websites for 9 of the top 10, looking at design and layout. While I was at it, I noticed that the text size on nearly all of them was very small -- and column width too wide for the small text. And I found that 6 of them used Arial, 1 Verdana, 1 Trebuchet, and 1 Proxima Nova.
MY commentary: "blech."
If you'd care to recommend, I'm interested in your opinion on a great sans typeface for web body text. Assume delivery over Typekit, Google Web Fonts, or comparable service. Neutral, readable; up-to-date, professional. Used at a slightly smaller size than you would probably want to suggest.
These sites frequently use the same face for Heading and Subheadings -- in other words, the whole page is one face, with the exception of the logo (which is whatever). In case that's relevant to your recommendation.