Green Giant Arborvitae are considered “deer resistant”. They aren’t “deer proof” though.
Upright Junipers are also “deer resistant”.
“Deer resistant” simply means that they won’t be bothered as long as there is other forage. During a harsh winter, they will be damaged.
Nothing is actually deer proof. Deer netting in fall is the only way to totally protect them. In spring, there is other, more desirable forage for them so they are safe during the growing season.