My Pyrenean is now 11 years old and will be dead in less than a month. He's 83cm at the shoulder and is very very fat, weighing 70kgs. He's a wonderful dog and I am going to miss him.
Some background info on Pyreneans: They were bred to guard livestock in the Pyrenean mountains. There are records of them taking on bears one on one. They could just barely win a fight with a bear if they had a spiked collar to protect their throat. Of course afterwards the dog wouldn't survive for very long either.
The French royalty somehow got hold of the breed and bred them to guard their royalty, giving them a most wonderful temperament in the process.
I second Parent in the Teddybear aspect. They are an very intelligent breed of dog and will unfortunately question nonsense orders.
I would highly recommend this breed to anyone, provided they have somewhere to take them on long walks.
Also, Parent: Be sure to introduce the livestock as friends before turning them loose on the land, unless you want freshly slaughtered 'intruders' on your hands!