Could you give a bit of a hint about age range: grade school, high school, college?
My kids read The Chronicles of Narnia before I did. That’s how I discovered what I’d missed.
My favorite piece of Catholic fiction is Brideshead Revisited by Evelyn Waugh. if you decide to watch it after you read it, do the 10+ hr miniseries which is _very_faithful to the book rather than the short version which strays.
I recently read The Dark Horse by Rumer Godden. Age recommendation: Upper Elementary/middle school, with parent discussion, through adult. Great story, great writing.