http://en.wikipedia.org/wiki/Core_fonts_for_the_Web
Here’s a demo I put together.
http://www.pagepipe.com/testx/
These are going to be the fastest loading. From my experiments with web fonts, they can really increase pageweight. Especially for extreme optimization for tablets. Some sites allow you to trim the web font set. like FontFonts. These are expensive fonts. Not worth the grief. Color and size is more important.
Ah! The shock of such a limited font palette.