To choose a right screen font around us, we can refer to our real world examples to understand this.
Apple
Apple’s celebrated “Aqua” interface, used in their OS X series of Operating Systems, is one of the world’s most recognisable, usable and beautiful GUIs available. Undoubtedly, a vital part of the Aqua look is in the font used – Lucida Grande. Such is the popularity and beauty of this font that it has become widely used as the body text font on websites all over the internet. It is, for example, Facebook’s primary font.
Windows
And in the world of Microsoft Windows, the release of their Vista OS also introduced a brand new GUI named “Aero” – featuring translucent ‘glassy’ windows, glossy buttons and a brand new system font called Segoe UI which is my favourite can read at a very small font size, legible, readable. Segoe UI is an excellent humanist sans-serif that has proven to be very popular and highly legible to boot. MS continued this font in Win-7 as well.
Some of the best SANS screen fonts
ALLER SANS
PT SANS
DROID SANS
M PLUS
CARTOGOTHIC
Hope this helps....