arial unicode, because it supports nearly everything. its nice having one font that works for nearly every major world language... i hate seeing ????????????? or code number squares.
Comic Sans, the font of all schoolkids around...used to think it was okay, but now can't stand it, especially for notices. Segoe UI and its variants, or Calibri here. Segoe UI Light would be perfect, but too thin to be readable in documents for the most part IMO. On a display anyway, in print, I wouldn't know.
Times New Roman - because I'm conservative. Arial or Verdana works as well. You know you are among nerds when fonts are the topic of discussion...