For younger kids, stories with simple plots and colorful illustrations about characters being brave and unique can be great. Like stories of a little mouse who doesn't follow the crowd to find its own way.
For older kids, more complex tales that explore deeper themes of individuality and acceptance. Such as a story of a teenager in a strict society who stands up for his beliefs and changes the community.
For middle-aged kids, adventure stories where the protagonist overcomes challenges by being different could be interesting. Maybe a story of a child who loves science in a world of art lovers and still achieves success.