I see no mention of :
Raymond E Feist
Just one of many SCI-FI authors whose work I enjoy.
Fiction & Fantasy are indeed very different genres, but lets not get too pedantic !
Room for both in my skull 
fred
Since Hunter S. Thompson has not been mentioned, I will put in a good word for the doctor.
I don’t think Joseph Heller has been mentioned yet. A lot of Closing Time shot clear over my head, but Catch-22 alone is enough to make him top my list.
Twain would probably be second.
I’ll go with those two statements, but wonder “When will you make an end?” at Robert Jordan (and I wouldn’t say best, exactly.
Add:
Dumas, Austen, Dickens, Douglas Adams, Scott Adams, Card, McCaffrey, Tokien, definitely, oh, this is hard…, King and Koontz, sometimes (when they aren’t turning out garbage)… I’m sure I’ve left someone out…