If popularity = quality Twilight would be the best Fantasy novel of all time.

Expand your Horizons:
Raymond E. Feist
Jim Butcher
Michael J. Sullivan
Brian Sanderson
Lindsay Buroker
Aaron Pogue
Cristopher Bunn
Peter V. Brett
Naomi Novik
Michael G. Manning
Daniel Suarez
Neal Stephenson
Neil Gaimen
Clay and Susan Griffith
Lawrence P. White
K.C. May
Glenda Larke
Philippa Ballantine
Kevin Hearne
Jill Williamson
Patrick Rothfuss
L. E. Modesitt Jr.
Dave Duncan
Brent Weeks
F. Paul Wilson