There is a blog site at http://www.onlineclasses.org/blog/ that has recently published a list of their choices of 100 All-Time Best Historical Fiction Titles.
Some favorites mentioned are:
Forever Amber by Kathleen Winsor
Katherine by Anya Seton
The Sunne in Splendour by Sharon Kay Penman
The Thorn Birds by Colleen McCullough
World Without End by Ken Follett
Check out their full list here. What would you add to the list?