Answer:
In bacteria cells, you would find pili (only found in bacteria and archaea) and DNA not contained in a nuclear envelope/nucleus. These are, for the majority, exclusively found in bacteria cells.
In animal cells, you would find lysosomes and centrosomes. These organelles are exclusively found in animal cells.
In plant cells, you would find plastids, such as chloroplasts or amyloplasts. More specifically, chloroplasts are exclusively found in plant cells as they are necessary for photosynthesis to occur.
