Looking into my favorite genre, fantasy, there are quite a few. (This will get longer.)
Terry Pratchett writes the best humorous fantasy and he's a master of reflection. He once wrote that his discworld is a mirror of our world and it's astonishing how he manages to reflect social, every-day and even personal problems in his stories. His characters aren't wiser or better than we are and watching them struggle and solve their world's and their own problems is quite inspiring and motivating.
Late Robert Jordan is a master in creating real full-blooded characters and to show their development. He has quite a bunch of main characters and even if they are completely different, one is able to identify with most of them. Brandon Sanderson does a really good job in finishing his Wheel of Time epic. One of his talents is adaptation. I didn't consider it possible to pick Jordan's story up and write on like Sanderson does it.
Tamora Pierce writes fantasy books about (and for) girls. I'm neither female nor young but her truly magnificent writing style captivated me. I read her books more than once because I enjoy her style that much. There is a lot of heart and understanding how people work in her stories and she has splendid ideas.
Another female author with splendid ideas is late Diana Wynne Jones. Her books for children and young adults hold more every-day magic than any other.
I haven't read a lot of Scott Lynch (because he has published only two books so far) but his pace is amazing. And every time you think the protagonist couldn't get deeper in the mess, it gets worse. Fascinating and quite entertaining.
Last but not least Neil Gaiman earns a place on my list. His short stories, especially 'Smoke and Mirrors', inspired me to write some of my own. He writes a darker fantasy than most and does a really good job at it.
That often depends on who I've read lately. Case in point, I just finished Their Eyes Were Watching God with my 11th grade students. I love Zora Neale Hurston. Her writing is luxurious and poetic. I get lost in the beauty of her words and I never tire of that book. I feel the same way about Steinbeck. On the opposite side of the spectrum, I love Hemingway for his economy, but I can also admire writers whose works I don't particularly like. For example, I dislike Catcher in the Rye, but I truly do admire J.D. Salinger's style. The novel is brilliant as a literary work, but I just find myself annoyed with Holden's spoiled, whiny attitude.
“Well known” in my incestuous little writing/reading circle might not be well known to a larger audience, so I’ll give both. Brian Evenson, Jose Saramago, Stephen Graham Jones, these guys simply do not disappoint. Some bestsellers I admire are David Sedaris (nobody can write humor like him), Mark Z. Danielewski (nobody integrates visuals into his writing without sacrificing the story’s integrity like him), and Malcom Gladwell (nobody makes seemingly boring ideas interesting like him).
Hemingway, Lovecraft, King, Clancy, Crichton, Grisham.
Well, with no doubt...my mentor...Walt Disney...:)
I admire a lot of writers, currently the top ones are Douglas Preston and Lincoln Child, C J Cherryh, John Scalzi, Robert Littell, Ursula K Le Guin, and many many others.
Kafka, Burroughs, Lethem, Selby, Winterson, DeLillo, Selby Jnr, Peace
I like Carolyn Keene, Brian Jacques, Dixon, Joan Lowery Nixon, Terry Brooks, and some others.
Suzanne Brockmann, Karen Robards, James Patterson, Karin Slaughter
Terry Brooks, J.R.R. Tolkein, Gene Wolfe, Paul Laurence Dunbar, Billy Collins.
I mentioned earlier my 3 faves are: Terry McMillan, (The late) E. Lynn Harris; Dean Koontz and I need to add, Alex Wheatle to my list. I've recently learned of his work since moving to London. He's another fascinating story-teller.
Leonardo Da Vinci
and my super guilty pleasure is 'Dan Brown novels'
Peter David is my favorite. He writes in a way that is smooth and easy to read.
One writer I admire a lot right now is Dean Koontz. He writes in the horror/suspense genre and really keeps you reading but at the same time manages to sprinkle in these amazing bits of humanity and wisdom. I would love to be able to do that. I prefer a dark, gritty sort of realism that nevertheless lets you see hope and good things, too - think Dick Francis, Ed McBains early work, very few current writers seem to really do that. I'd like to. I miss hard core reality adventure type writing with action that makes sense, risk you can feel, and a strong story with real people who have flaws and fears and who sometimes make bad decisions.