I THINK the term is "self-insert"
in which the protagonist knows about the lore and the characters of a specific fiction.
My first experience with this kind of fiction was with the author Princess Alexandria who did mostly x-men fan fiction. I was indifferent to the x-men franchise and read her stories because she was constantly on the best femslash lists. She wrote very good fictions with that premise and her OC character later jumped through other dimensions into fictions like Gargoyles, Twilight, even Voyager.
Well, enough about her, I wanted to get recommendations and not babble about another author ^^
The few fiction's about self-insertions, that I read were either hit or miss. Alexandria's OC character was aware of the lore of the fictional Universe she jumped into but wasn't 4th wall breaking. She was a character that read books about that Universe and was a character in her own fictional Universe. She is the only survivor of a post-apocalyptic world and has to integrate into a world, that was to her knowledge only fiction.
on the other end of the spectrum, we have the self-aware 4th wall breaking character that knows he is in a story. The majority of these stories have the element, that the author himself is inserted as a character into the story. (ergo: self-insertion). That's hit or miss, but mostly miss. It can work if the story itself isn't taking itself seriously.
So, any recommendations? :)