There are too many to name, but some are more interesting than others.
The skin is the most vital organ. It keeps all the others inside where they belong.
Next in importance is the neck. Without it the head would fall into the stomach and be eaten alive.
Third in Didge's list of vital organs is the nose, which not only allows us to sniffle and breathe and snub people, but is also proof that we were the result of Intelligent Design. Just think about it: If the nose wasn't located exactly where it is, in exactly the shape it is, where would we place our spectacles?