To throw the question back at you: what are some authors you like to read?
Personally, off the top of my head, besides classics ... Jennifer Weiner and Carlos Ruiz Zafron both have freebies in the Kobo store that I've downloaded and enjoyed. I'd have to go back and look at what else was free that I enjoyed.
But if you're, say, a sci-fi fan, my suggestions wouldn't help you.
One of these is chick-lit and the other is mystery/suspense.