What Organelles are the most critical for cell survival?

All organelles in a cell, belong there and serve a purpose, without a one major organelle the entire cell would function differently. Each and every cell in the body is like a machine that needs to function with every piece of machinery and enough workers to get the job done. Although I do believe that the nucleus is absolutely essential to a cell; without it, the cell's life would cease to exist. It stores hereditary information in DNA, and it synthesizes RNA and Ribosomes.The nucleus is basically the control center of the cell, like the brain to our bodies.