My favorite characters from Stephen King have to be Christine, the Hotel in the Shining, the kids in "IT", and the Gunslinger.
Christine because she's a kick ass car that's ALIVE.
The Hotel in the Shining because I live in Colorado and am quite familiar with the ghosts of the Stanley Hotel in Estes Park.
The kids in "IT" because they work together to fight evil.
and the Gunslinger because he's an unique character from a man known for 'horror' stories. The Gunslinger stories are bizarre westerns.