I don't know much of it as facts, just 90% from experience. I'll do Protoss for you.
Protoss- Zealot - Max damage against all armor types.
Dragoon - Half damage against light armor, max against all others.
Dark Templar - Max damage against all armor types.
Reaver - Max damage against all armor types.
Corsair - Max damage against all armor types.
Scouts - Max damage against all armor types.
Carrier - Max damage against all armor types.
Arbiter - Half damage against light armor, max against all others.
Well i think that's correct. I don't know the nitty gritty such as each type of armor and each type of damage. I think we'll need to consult AoP for this!