I actually very rarely go out and buy books right when they come out, mostly because they are expensive and I am still a poor college student. I utilize the library as often as possible and usually just buy books that I love. However, in an ideal world these would be my auto-buy authors in no particular order:
Cinda Williams Chima
Sarah J. Maas
Bonus: C.S. Lewis, Edgar Allan Poe, and Jane Austen, if they were still alive and writing.