Serious fiction books you can get lost in?

My boyfriend and I are trying to start a tradition of giving each other a book before the holidays and reading together on the slow and cold days off around thanksgiving/Christmas/new years. He doesn’t read too often, but lately I’ve seen him reading non-fiction.
I asked 3 “either-or” questions to try and come up with book ideas:
1. Fiction or Non-Fiction?
2. More comedic or more serious?
3. A book to make you think or a book to get lost in?

And he answered fiction, more serious, and book to get lost in.

Any suggestions?

by soccer439