I've been doing some research, and determined that all the screens that cause me migraines use polarizing filters in some form.
Migraine/headache list:
IPS LCD - uses polarizing filters
TN LCD - uses polarizing filters
AMOLED phones - uses polarizing filters (to reduce reflection/increase perceived brightness)
No headaches list:
Plasma
CRT
Might interest some, due to this I might try out a DLP projector - as they also do not use polarizing filters to produce an image.