In reply to Webfont: a legible, good quality grotesk/serif combination. Choices and alternatives:
I personally like Paratype's PT Sans/Serif, but some folk dislike them for the detached tail on the 'Q'
Hi Té, thanks for the suggestion. I'm afraid I'm among "some folk". Have you spotted them in use on a website? If so, It'd be nice to have the link.