I'm somewhat hesitant to post my list, as I imagine some of the entries will be met with a fair bit of derision, but I want to answer Mav's question (as I understand it) honestly. These are not the best authors I have ever read, but they are the ones whose work has influenced me and my understanding of the language the most. Keep in mind that I am among the younger Board members, and I went to a high school (and colleges) that largely frowned upon reading only "the canon." In no particular order:

William Shakespeare
Arthur Miller
Ray Bradbury
Dr. Seuss (Theodore Geisel)
Emily Dickinson
John Steinbeck
J. D. Salinger
Stephen King
Toni Morrison
Douglas Coupland

Near misses include Twain, Frost, Asimov, Shirley Jackson, and Philip K. Dick.