Where to start.............
East of Eden, Grapes of Wrath, Of Mice & Men, To A God Unknown...........Steinbeck
Catch 22.... Joseph Heller
One Flew Over The Cuckoo's Nest....Ken Kesey. Also a great movie but the book is so much better.
One Day In The Life Of Ivan Denisovitch....Alexander Solzenytsen
Lord of the Rings...JRR Tolkein
Angelas Ashes...Frank McCourt Anything by Myles na gCopaillin (Flann O Brien)

The Moon Is A Harsh Mistress...Heinlen
Lucifer's Hammer..........Larry Niven
The Wheel of Time Series...Robert Jordan
The Stand, The Shining, Needful Things, Misery, by Stephen King
Battlefield Earth...L.Ron Hubbard Anything by Terry Pratchett, but most especially the book he wrote with Neil Gainman, "Good Omens"
In the Balance, Tilting The Balance, Upsetting the Balance, etc....Harry Turtledove.

The Belgariad, & The Malloreon,....David Eddings The Many Coloured Land...Julian May.

NO, MUST STOP TYPING, GOT TO GO & READ SOMETHING...... Eddie