Not sci-fi, but Mister B Gone by Clive Barker was really good. The book is a conversation with a demon who is telling you his life story. It is the story of how he came to be trapped in the book you are reading.
I thought the book was super funny and surreal. I saw reviews after finishing that it is considered some of his worst work. That might be true, but the worst 24 carat bar of gold is still a 24 carat bar of gold. Well worth the read imo.