Lord of the Rings just about saved my life in high school. Possession by A.S. Byatt. Foucault’s Pendulum by Umberto Eco. Oryx and Crake by Margaret Atwood, though I’ve yet to read the sequels. Atonement by Ian McEwan. Just about anything by Geoff Ryman, Ali Smith, José Saramago, or Sheri Holman.
Your taste seems like exactly the sort of thing I'd enjoy, do you have any specific suggestions for someone who absolutely loves Eco's metafictional novels in particular and metafiction in general? (Aside from Possession, which I've never heard of but is going directly on my to-read list)
I recently read How to Live Safely in a Science Fictional Universe by Charles Yu, which I really liked. It is science fictional, though, but maybe not…maybe more surreal. Jorge Luis Borges, Italo Calvino, David Markson. I started Dictionary of the Khazars by Milorad Pavić many years ago, got interrupted, and haven’t got back to it, but I definitely need to because it was so intriguing in form.