I will first give the function of the organelle, and then explain how it is related to a certain part of a city.
Mitochondria: This is known as the power house of the cell. It basically converts forms of energy into something that can be utilized by the cell. In city, these would be your power generators, or power plants. They convert energy (e.g. mechanical) into electrical energy, that can be utilized by the whole city.
Golgi Complex: The golgi complex or golgi apparatus modifies proteins and packages them (for protection) before they are transported to various destinations where the proteins are needed. In a city, something that 'packages' or 'distributes' something could be a post office (which distributes mails) or a store's packaging center (which distributes the goods).
Endoplasmic Reticulum: There are two kinds of ER - smooth and rough. The rough ER, so-called because of the attached ribosomes (workers), is responsible for protein synthesis. The smooth ER, on the other hand, is concerned with lipid and carbohydrate metabolism. As they produce various materials used by the cell, ER could be the factories of the city. After the ER, proteins are passed to the Golgi Complex, just as factories transfer goods to delivery centers.
Ribosome: These are responsible for protein synthesis by linking amino acids together. Ribosomes can be found in the rough ER. We can therefore say that they are the laborers/workers in the factory since laborers/workers are the once who actually does the work to produce something in the factory. They can also be small facilities/units inside the factory, that specializes on some specific product.
Lysosome: The lysosome is known as the suicide bag as they are responsible for breaking down waste materials and other cell debris. Thus, they can be likened to demolition services of a city - or perhaps a landfill. Demolition services are contracted in order to destroy some old building to create something new. Landfills, on the other hand, are where wastes are placed - either for recycling or decomposition. Wastes of a cell, can also be recycled after degradation by the lysosome.
Cytoplasm: This is the gel-like substance inside the cell where all the organelles are floating. Most of the reactions (i.e. cellular activities) in a cell occur in the cytoplasm. There are two ways to translate this to a city. First, it can be the 'lot' or the land in which the city is built. This is because the land is where the city actually stands, and hence anything that happens in the city is possible only because there is a land which could facilitate all this. Another possibility is that the cytoplasm is the community that lives in the city. The community is responsible for any activity, without any community, a city will be empty and incapable of any activity, just as a cell would be practically dead without the cytoplasm (where everything is facilitated).
Cell Membrane: The cell membrane separates the interior of the cell from the exterior. It is a semi-permeable membrane which means some substances can pass through while others can't. It controls what goes in and what goes out of the cell, and helps in regulating the cell's contents (e.g. ions). This is the boundary of the city. It can either be the city's wall (or a state line). However, probably a better analogy would be a check point before one enters a city, or the toll gates. These structures facilitate migration to and from the city, and hence controls what goes in and out of the city.
Very good - perfect analogies