Very few movies based on his books have been good, whereas the books have been great. The only common problem King has with his books (and apparently his son doesn't have
) is ending his stories. Anyways, good Stephen King movies:
Shawshank Redemption (Based off Short Story)
Delores Claiborne
Stand by Me (Based off Short Story)
The Mist - Arguably Good (Based off Short Story)
The Green Mile - Arguably Good
The Lawnmower Man - I liked it haters (Based off Short Story)
The Dead Zone
Christine
Catching the theme? When he is engaging in drama or doing short stories, they translate well.
As to good books, The Stand is his best. I'd say The Shining is second (Kubrick's version is only slightly like it, despite being awesome), and Pet Semetary the third (ignore the movie on this one, it cheapens it tremendously).