There are plenty of options. It is nice to settle on one.
DejaVu offers the best balance between Unicode support and ease of reading both Serif and Sans Serif.
Here is how to specify it with XeTeX
:
\setmainfont{DejaVu Serif} \setsansfont{DejaVu Sans}[Scale=MatchLowercase] \setmonofont{DejaVu Sans Mono}[Scale=MatchLowercase]