Hi Ascendedmind,
Pillows are a very personal part of a sleeping system and while there are some basic “needs” in a pillow … most of a pillow choice is based on each person’s personal preferences.
A pillow needs to keep your head and neck in good alignment in all your sleeping positions so different sleeping positions and body types need different thicknesses or designs based on the “gaps” between the head and neck and the surface of the mattress (generally thicker for side sleepers, in between for back sleepers, and thin or no pillow at all for stomach sleepers) but the choice of material and “feel” is strictly a personal preference.
I currently sleep on a shredded latex pillow for example while my other half likes her memory foam pillow.
There is more information about pillows and links to some good resources and some of the forum threads that discuss them in the pillow thread here.
Phoenix