Large Holes - general use - cheese, carrot etc.
Small Holes - parmesan* when feeling lazy or when I'm grating it to go IN food (as opposed to ON).
Parmesan - parmesan for use as a condiment.
Nutmeg grater - yeah occasionally.
Slicer thing - never.

* Referring of course to authentic parmagianniano

TIP - Freeze your fresh ginger and grate it into your cooking..

Any Other Grater Business? What style is yours?