I can't tell you when I started collecting Stephen King stuff...but I got REALLY serious about it right about the time "The Green Mile" serial novels (paperback!) started coming out. Since then, my collection has grown quite a bit. I love every piece I've collected so far...but here are a few of my extra special favorites...
This part of the collection started with the 4-pack of paperback novels I got for Christmas one year. After that, I was WAITING for each book to come out! This series is a must-read!
The Dark Tower novels have been released as a series of comic books. Those individual comics are on the top of the bookshelf...but I did buy the hardcover collections when they came out. I also have a nice edition of the Creepshow comic.
I've found some SK rarities, including his Castle Rock newspapers and some magazines with first appearances of some of his more popular stories.
I scored a Rolling Stone magazine with a new SK short story in it.
AAAAND...the coolest items in the collection...a magazine article about the movie "The Shining" -- signed by Stephen King, Jack Nicholson, Shelly DuVall and others...and "The Shining" screenplay to go along with it. That's also autographed by many...but that's just a copy. Still pretty cool, in my opinion. : ) The two newest novels I've still not finished reading.
If you can help me find other Stephen King rarities...just let me know! I'm looking to fill the bookshelf with 'em!