The best one is the one that is already squeezed into juice.
I am hyper-sensitive to the citrus oil in the peel, which squirts out into a mist when you peel it by hand.
It not only gives me discomfort, at worst it can trigger migraine.
If someone peels it on a train, I have change car. If someone peels it on a bus, I have to get off and catch the next one.