Ouch this is hard. I haven’t read that many books so far. (I start so many, finish so few)
Possibly my favourite, in a very meta-fiction kinda way, was Black Boy by Richard Wright.
Firstly because I love what it said about reading, and secondly because Jim Crow and Apartheid are kissing cousins, and it’s fascinating to see my country’s worst parts reflected in the gleam of another. It also helps that it’s beautifully and economically written.