The first book I read by Orwell was 1984 in which I really appreciated his work. Then I searched for his other novels and found 'Animal Farm' quite interesting one. This book has a short moral story, depicting the founding of USSR and Stalin. The novel describes not only the corruption of the revolution by its leaders, but also how greed and ignorance can destroy any society.

PLOT: The animals of the farm are tired of being under the cruel hands of farmer Jones(human). So the old major of the farm (a pig),adjudges man as their enemy. Animals think it is the start of a better life. Their dream is of a world where all animals are equal and all property is shared. But soon the pigs take control and one of them, Napoleon, becomes the president of all. One by one the principles of the revolution are abandoned, until the animals have even less freedom than before. Soon all rules change, showing that all animal are equal but some are more equal than others.

In my opinion, the 2 main character highlighted to describe the political system are Napolean(an example for leader) and boxer(an example for society)

Napoleon : He exercised all powers in a cruel way. He gradually changed the Commandments for his benefit and started behaving similar to humans against whom they originally revolted.
This character was metaphorically used for those group of people who show themselves smarter than others and persuade all to trust them and appoint them as a leader.

Boxer: He was quiet a loyal, hardworking character, with full of dedication. He was physically the strongest animal on the farm, but slow. His ignorance and blind trust towards his leaders leads to his death and other's profit. Profit because boxer was the one who had the strength and leadership to overthrow Napoleon. Boxer's work ethic was often praised by the pigs too.
Here this character basically used to show that how people blindly trust their leader by giving their life in hands of them. But ultimately what they get in return is all sorrows. And that's because of the powers they misuse and the greed of leaders make them to do.

The unique thing about this book is first of all its thickness, consisting around 100 pages. Secondly it can be understandable and accessible by any person of any age group. It can even be appreciated as a story by children with no understanding of the political message at all.
I would say if you haven't read it, read it at least once. It's worth reading.