I have wanted to read this book for ages and I must say, I'm glad I didn't, because that meant I got to enjoy it now :D It was one of the best thrillers I've read in ages - despite all the work I had to do, I kept going "Just five more pages, just five more pages..."
I have mixed feelings about the characters - on one hand, I loved them and thought they did exactly what they were meant to do, but on the other I felt that the way the text treated Annie was incredibly problematic. I am still giving the book 5 stars because I feel that the fact that it is written from Paul's viewpoint mostly explains it, but the way mental illness was treated still left a very sour taste in my mouth.
If you can tolerate that, and don't mind brutal stories that aren't afraid to go into detail, I definitely recommend "Misery". It is a very good psychological study, as well as a very interesting look into the mind of a writer, and it definitely won't leave you bored.