/usr/local/lib/share/tex/fonts  
	cm: computer: modern fonts used by our applications usually.
	tmf: texmetafonts: fonts used by tex
        pk: printer ??: fonts used by ps and dvi (therefore by printer)

/usr/local/lib/share/tex/xfonts directories with fonts of different machines. 

you should be safe on all our applications by using fonts from 
/usr/local/lib/share/tex/fonts/fonts