Muscle cells, particularly cardiac muscle cells, are likely to have the most mitochondria. Mitochondria are known as the powerhouses of the cell, as they are responsible for producing energy in the form of ATP through a process called oxidative phosphorylation.
Muscle cells require a significant amount of energy to support their function, especially during contraction and extended periods of physical activity. Cardiac muscle cells, which make up the heart, are especially reliant on aerobic respiration to continuously pump blood throughout the body without fatiguing. To meet their high energy demands, these cells contain a large number of mitochondria, which enhances their ability to produce ATP efficiently.
In summary, due to their high energy requirements for sustained activities, muscle cells, specifically cardiac muscle cells, have the most mitochondria compared to other cell types.