In a similar vein, my answer to this thread would be the Count of Monte Cristo.

I was expecting a ‘historical yawn fest’, but i was completely captivated by the story. I was immediately drawn into how intricately woven and complex it was. I know many people dislike the Italian chapters, but I even enjoyed them. With chapters like those, I felt Dumas gave an extra layer of depth to the characters, that you don’t find in most novels.

I went into the novel kinda dreading it for being a really long ‘classic lit’ drama, but its now one of my favourite novels.