Who is the best living horror writer?
The obvious, and most popular answer, is of course Stephen King. I almost agree, but King has done too many different types of fiction to be stigmatized as merely a horror writer. A lot of it can even be construed as science fiction. Especially when one considers how psi talents were an SF staple for years and years.
Despite my love of his work my answer is not Stephen King. I’d have to go with the inimitable Ramsey Campbell.