How to Counter Marauders

Marauders are a very versatile and strong terran unit. They can be deadly in early and late game and it be best they be dealt the iron fist. They are especially useful because of them amount of upgrades you can give them (stim concussive shells and attack and armour.) Their armoured qualities allow these metal pumping bastards to soak up damage like a sponge, but how do we get around this seemingly impossible mix.