Ed Greenwood first, JRR second, Elaine Cunningham, Glen Cook, Lieber all tied for third. Will have to try Erikson now after such a strong reccomendation. Martin and Jordan would be in the next five led by Michael Stackpole.
Bram Stoker, the good ol' Irishman. He wasn't the first to write about vampires, but he wrapped it in a complex tale that has sparked hundreds (possibly thousands) of stories about vampires for centuries to come. Then JRR, and third goes to JK Rowling for inspiring countless young children to crack open books and read. I have no data to support this save what I saw in my own daughter and heard from her friends and other parents. Good article/blog/letter/whatever the hell you call this. :>)