I have lots of favorites, especially those from my writing groups, but my very favorite authors have to be Mary Higgins Clark and the late Sidney Sheldon.
What makes them favorites is their style is easy to read, yet not dummied down. Their plots are compelling, yet not too complicated to understand. Mary usually writes about everyday people, while Sidney's books tend to be about the larger-than-life ones.
Which ones are your favorites, and why?