If you haven’t had a chance to check out the font that Google announced a few weeks ago – seriously, check out Open Sans, by Steve Matteson.
I feel like this one is the gem in the crown for Google fonts. It’s a real workhorse type sans-serif, but one designed with web in mind. It’s like Helvetica in it’s utility, but screen friendly like Verdana. But unlike Verdana, it’s not ugly over 11px.
I hope to see this one used on a LOT of websites in the future.