My top five:
JK Rowling (Harry Potter)
JRR Tolkien (LOTR)
Michael Crichton (Jurassic Park, the Andromeda Strain)
Patrick O'Brien (Master and Commander)
John Grisham (The Client, The Summons, the Firm)
Sylvia Plath {The Bell Jar, various brilliant poems}
George Orwell {1984}
Carolyn Keene {Nancy Drew}
F. Scott Fitzgerald {The Great Gatsby}
Mercedes Lackey {Mage Wars series, I think it's called}
in no particular order:
JRR Tolkien
Barbara Kingsolver(i have read poisonwood at least six times and the bean trees twice! :mellow
Cecilia Ahern(her first book, which was just released is phenomenal! wonderful fluff!)
Sophie Kinesella(amazing fluff! been with these books from the beginning..too bad no more, cant wait till Cant KEep a Secret!)
Amy Tan(love love her books!)
Jane Austen
Hawethorne(i was the only one in my class who loved the Scarlett Letter!)
Betty Smith(Tree Grows in Brooklyn)
Jk Rowling
Top Fifteen in alphabetical order
Jean M. Auel
Anne Bishop
David Brin
Orson Scott Card
Sara Douglass
Robert Jordan
Mercedes Lackey
Anne McCaffrey
Larry Niven
Philip Pullman
Jennifer Roberson
J. K. Rowling
Pamela Sargent
J. R. R. Tolkein
Joan D. Vinge
Caroline B. Cooney (she wrote all those face on the milk carton books and other series)
Meg Cabot (princess diaries!!)
Barbara Kingsolver (bean trees, poisonwood bible...)
Scott O'Dell