In no order and all over the place:

George RR Martin
Ed McBain
J.R. Ward
Brent Weeks
Anthony Ryan
Sandrine Gasq-Dion
T.A. Chase
Michael J. Sullivan
Maryjanice Davidson
Catherine Coulter

Maria V Snyder
Donna Hatch
Sarah M Eden
Jennette Green

Carlos Ruiz Zafon
Philippa Gregory
Elizabeth Chadwick

Billy London
Lora Leigh
Christine Feehan
Sherrilyn Kenyon
Shelly Laurenston
Nalini Singh
Kristen Ashley
Nora Roberts
NOT ALLOWED
Lynda Chance
Linda Howard

Hermann Hesse
Fiodor Dostoievsky
Kafka
HP Lovecraft
Jostein Gaarder
JK Rowling
Neil Gaiman
Arthur Conan Doyle

Neil Gaiman
Anne Bishop
Jaqueline Carey
Sharon Shinn
Charles De Lint
SM Stirling
JK Rowling (although after attempting Casual Vacancy I might take her off the list)

Jeffrey Archer
Mary Higgins Clark
Julie Garwood
Johanna Lindsey
Dana Marie Bell
Shelley Laurenston

sarah dessen
charles dickens
ayn rand

Let's see...

Stephen King
J.R.R. Tolkien
Joe Hill
Neil Gaiman
Rainbow Rowell
Mario Benedetti
H.P. Lovecraft
Ray Bradbury
Jane Austen
Oscar Wilde

I'm sure I'm missing a lot of them!

Tom Clancy
Stephen Hunter
Lee Child
Clive Cussler
Brett Battles
Lincoln Child
Douglas Preston
Michael Connelly
John Connolly
Jeffery Deaver
Dean Koontz
Stanislav Lem
Alistair MacLean
James Rollins
Robert Sheckley
Clifford Simak
Strugatsky brothers
Brad Taylor
Roger Zelazny

Lois McMaster Bujold
Anne Bishop
Nalini Singh
Patricia C. Wrede
Laurell K. Hamilton
Kaitlyn O'Connor
Ilona Andrews
Gini Koch
Tamora Pierce

Patricia Briggs
Jane Austen
Quinn Julia
Cole Kresley
Mead Richelle
Showalter Gena
Cabot Meg
Hunter C.C.
Bell Dana Marie
Armentrout Jennifer L.
J.K Rowling
Montgomery, L.M.
Stephen King
Terry Pratchett

Marion Zimmer Bradley
Anne McCaffrey
Isaac Asimov
Robin Hobb
Lois McMaster Bujold
Lynn Flewelling
Orson Scott Card
Robert J. Sawyer

Damn... Let me check.
Well off the top of my head:
Jules Verne
Alexandre Dumas
Jack London
Charles Dickens
Rick Riordan
J.K. Rowling (only with Harry Potter though)
Ilona Andrews
Melissa Landers
Leigh Bardugo also has a smooth writing style, so yeah.

John Steinbeck
Kurt Vonnegut
Margaret Atwood
Jack Kerouac
Jane Austen
Chuck Palahniuk