If you love Stephen King you HAVE to read the Gunslinger series. Almost every book he's ever written is connected to it. If you admire his gift for writing now, you'll be astounded when you see how it all weaves together.
Lisey's Story was great, too.
BTW, the Outlander novels by Diana Gabaldon are fabulous. They're romance, history, science fiction, adventure, and drama all rolled into 6 or 7 seriously long books. If you try them, you'll be addicted.
Kelly