A.D. Hall

Coffee.

Steinbeck - Cannery Row is my favorite because of the dialog. He tells it through wonderful dialog. And I think you would be hard pressed to find many three or more syllable words in the book. Which means I can read it.
Hemingway - Islands in The Stream. In that book he describes a lunch of grilled fish on a boat in the gulf stream that always makes my mouth water, and is my reminder not to forget taste, smells and sounds when writing descriptive narrative.
Elmore Leonard - everything - having just come off a summer-long Zane Grey and Louise La'mour binge as a teen, I was amazed to find his early westerns - books that were so much better! If I learn to write half as good as Elmore Leonard I'll be happy.
Charles Bowden - Frog Mountain Blues. Those who don't know him, go check him out. He passed away only last year, bless him. His writing is vivid, meaningful and informative - all the things I want to do.
Sir Ernest Shackleton - Endurance. The most incredible story ever told.
Wait, only five? I haven't mentioned Mark Twain!