But yeah Dostoevsky sums up the Orthodox spirit fairly well in his works. He doesn't go into theology really but I think it's good for an Orthodox (or any) Christian to read his books for spiritual reflection.
Dante is fairly well in line with Catholic thought I believe.
I haven't read Paradise Lost yet but people have recommended I read CS Lewis' preface to it beforehead. CS Lewis is probably my favorite fantasy writer so I'll have to check it out.