I spent my whole life up until 4 months ago not reading any of his books even though I love horror. I read Thinner and loved it. Since then I've read 14 books and loved each and everyone. I'm reading Cujo at the moment and getting ready for the GOODBOY to break my heart and make me cry.
11.22.63 was unexpectedly brilliant for a timey wimey romance focused on Lee Harvey Oswald. Nothing compares so far to IT though. Pet Semetary also genuinely scared me but I guess it's because my son in the same age as Gabe in the book.
just a small warning: The Gunslinger is veeery different to the rest of the saga. the rest is closer to the other King's books so you might either like them more or feel disapointed by the narrative change.