In no particular order:
Ender's Game/Shadow series - Orson Scott Card
Black Jewels Trilogy - Anne Bishop
Chronicles of Thomas Covenant (Series 1, 2 and 3 in progress) - Stephen R. Donaldson
The Quickening - Fiona McIntosh
Chronicles of the Raven - James Barclay
Everything by Sara Douglass
Everything by Elizabeth Haydon
Crown of Stars - Kate Elliot
ColdFire Trilogy - CS Friedman (and Madness Season is a standalone Sci-Fi)
FarSeer Trilogy - Robin Hobb
GodSlayer Chronicles - James Clemens (aka James Rollins)
Kushiel - Jacqueline Carey
Codex Alera - Jim Butcher
Sword of Shadows - J. V. Jones (although this author is very disappointing lately as her book publication schedule has been pushed out to more than 2 years between books)
bah...too many to fit into 10