Download Noto Font - Because It's One Font That Rules All!
I really like the idea and something I always wished existed. That said, the font's available in various forms: Serif, Sans Serif (mostly used for English) and then all your regional languages. Google's published a map of the world to indicate which parts of the world (and their languages) have been covered. It's quite possible that a language may not have been covered; but be assured that Google folks will cover everything!
You may download the font from : #-Link-Snipped-# . Do give it a try! It's worth it!