Papillon - Henri Charrière, Patrick O'Brian There's some dispute over whether this is 100% factual, but even so it's a good read.
Henri Charriere is sent to the French penal colonies after being set up.
Tells of his time on the islands and various escape attempts.
It's told in an engaging style, and he brings other characters to life. Some of his choices seem self-defeating, and even wanting revenge doesn't always answer why he gives up a good life he is making.

He lays things on a bit thickly when he explains the inherent decency of all the other convicts or natives he runs across.

Overall, it's a well told tale of being given a bad deal and making something good out of it.