I’m taking ‘best’ as how we felt about them at the time we read them, so:
Marian Keyes - is it ‘Lucy Sullivan is Getting Married’? I can’t even remember the plot, but it was the first chick-lit I ever enjoyed, so it stays with me for that reason.
Read a lot of everything while working in a second-hand bookshop or 4.
Susan Howatch: the Starbridge series. Also The Wheel of Fortune.
Stephen King: The Stand, Insomnia, Christine.
Elizabeth George: A Great Deliverance, A Traitor to Memory, Well-schooled for Murder and most other early ones.
Dan Simmons: The Fires of Eden, The Terror.
Macbeth.
Barbara Vine - all of them.
God I could go on for ages 
And that’s not even starting on books I read as a child... Jan Marks ‘They Wait and Other Stories’ stands out massively but there are so many others.... wanders off to Amazon.