You brain is considered to be the most important. However, you can't live without many of the rest.
All of the organs are very important. The most important is probably "the big organ" which is your intestinal organ. That is what the food eaten goes through after it is broken up, but before it reaches the toilet.
The largest or most important part of an organ is called the "parenchyma." This term refers to the functional tissue of an organ responsible for its specialized functions.
The small intestine.
The lungs.
lungs
The brain
carryblood
The Kidneys
The brain is the most important organ of the nervous system. The spinal cord and the brain are the main parts of the nervous system but the spinal cord is not considered to be an organ.
The Kidneys
skin!
small intestine