1. Dark Tower Series. I thought the ending suited him. Without it, he probably would not have been able to keep himself from writing an 8, then 9, then 10 book and so on...
2. Insomnia. The main character is just wonderful
3. Rose Madder. This book is really intense and quite terrifying
4. The Girl Who Loved Tom Gordon. I love how King makes his main characters, most of them, so independent and fit for survival (even an 11 year old girl).
I have not read The Stand or It, but I plan to once I am out of school.