Fall of Troy is also very good for sure! I think the reasons “Letters From Prison” will always appeal to me is a) the sheer variety of changes the characters undergo over the course of the story–I can basically find a chunk focusing on an given fetish I feel like nursing at the moment, and b) the internal struggle of the character is nice, but I especially like how he shifts over the course of the story from a reactive bottom into a top, essentially doing to someone else what his master first did to him. That realization moment is there too, at the end as well.