Webfonts.info the MyFonts webfonts showcase

Proxima Nova, combined here with Droid Sans, is fast becoming the standard UI font for sophisticated, consumer-facing retail brands such as Virgin Australia. It’s anonymous enough to never dominate a brand while having enough character to create an atmosphere different from Verdana or Arial; there’s an incredible choice of weights and widths within the family which allows for good layout flexibility and, of course, its rendering is consistently good on almost any platform.