In no particular order.....I'm looking through www.greatbooks.org
for inspiration, and am looking at the list and saying "oh, yeah, read that one and liked it...."
The Art of War
Anything by Poe
Any poetry by the Brownings, Keats, Shelley, other Romanticists
Much Ado About Nothing and Julius Ceasar (or other Shakespeare)
The Social Contract (Rousseau)
Letter from Birmingham Jail (King)
The American Constitution
The City of God (St. Augustine)
The Republic (Plato)
The Color Purple
Cuckoo's Egg (Cherryh)
Murder on the Orient Express (or a Miss Marple story)
Just for fun
The Dragonriders of Pern series
Those Who Hunt the Night
The Stainless Steel Rat
The Cat Who...
There's a start of a list, anyway.