[Hupo]

There's lots of great free-for-commercial-usage typefaces out there. If you don't already have Fontsquirrel[1] (who also has a fantastic @font-face generator[2]) bookmarked, you should fix that immediately. Google Web Fonts[3] is also another (obvious) resource.

[1] http://www.fontsquirrel.com/

[2] http://www.fontsquirrel.com/fontface/generator

[3] http://www.google.com/webfonts

Also, while I'm at it, I guess I could name some typefaces I've grown quite fond of: Alegreya, Aller, Cabin, Delicious, Fontin Sans, Lato, Open Sans, PT Sans, Puritan, Quattrocento Sans, Rosario, Source Sans Pro, Ubuntu. All great stuff!