Far too many to list. However, one series I really do keep meaning to read is Trudi Canavan's Traitor Spy Trilogy trilogy which is a sequel to her Black Magician Trilogy. Of course I'll have to reread the first trilogy first *g*
I seem to recall I found them on Amazon when browsing or they might have popped up in a recommendation - it has been some time since I bought them.
They interest me because I've read the first trilogy and I do like to follow things through.