This is just a phenomenal collection of epub books.  I found them on some random forum, hosted viaor something... so I take no credit or blame for quality.  I have not had time to examine them all but as far as I can tell, most are above-average quality.  There are some errors in some, but almost all are decently readable on an ebook reader.

Some of the books appear to be the same as in this collection: 
https://www.piratebays.to/torrent/5698246/2500__sci-fi_ebooks_in_epub_format (which by the way is also a great download).  ANd don't forget to check out this small set of epubs, too: https://www.piratebays.to/torrent/5613234/Epub_Collection


1984 - Orwell_ George.epub
48 Laws of Power - Greene_ Robert.epub
A Bend in the Road - Sparks_ Nicholas.epub
A Brief History of Time - Hawking_ Stephen.epub
A Briefer History of Time - Hawking_ Stephen.epub
A Case of Conscience - MacLeod_ Ken.epub
A Clockwork Orange - Burgess_ Anthony.epub
A Colossal Failure of Common Sense_ The - McDonald_ G. Lawrence.epub
A Farewell To Arms - Hemingway_ Ernest.epub
A God In Ruins - Uris_ Leon.epub
A New Earth - Tolle_ Eckhart.epub
A People's History of the United States - Zinn_ Howard.epub
A Scanner Darkly - Dick_ Philip K_.epub
A Short History of Nearly Everything - Bryson_ Bill.epub
A World Without Ice - Pollack_ Ph.D._ Henry.epub
Airframe - Crichton_ Michael.epub
American Gods - Gaiman_ Neil.epub
American Psycho - Ellis_ Bret Easton.epub
Anathem - Stephenson_ Neal.epub
Animal Farm - Orwell_ George.epub
Anna Karenina - Tolstoy_ Leo.epub
Apt Pupil - King_ Stephen.epub
Atlas Shrugged - Rand_ Ayn.epub
Blink_ The Power of Thinking Without Thi - Gladwell_ Malcolm.epub
Catch-22 - Heller_ Joseph.epub
Childhood's End - Clarke_ Arthur.epub
Children of Men - James_ P. D_.epub
Confessions of a Wall Street Analyst - Reingold_ Dan.epub
Cryptonomicon - Stephenson_ Neal.epub
DarkTower 7 - The Dark Tower - King_ Stephen.epub
Darktower 1 - The Gunslinger - King_ Stephen.epub
Darktower 2 - The Drawing of the Three - King_ Stephen.epub
Darktower 3 - The Waste Lands - King_ Stephen.epub
Darktower 4 - Wizard and Glass - King_ Stephen.epub
Darktower 5 - The Wolves of the Calla - King_ Stephen.epub
Darktower 6 - Song of Susannah - King_ Stephen.epub
Dirk Gently 1 - Dirk Gently's Holistic D - Adams_ Douglas.epub
Dirk Gently 2 - The Long Dark Tea-Time o - Adams_ Douglas.epub
Do Androids Dream of Electric Sheep_ - Dick_ Philip K_.epub
Drive - Pink_ Daniel H_.epub
Dune - Herbert_ Frank.epub
Enders Game 1 - Ender's Game - Card_ Orson Scott.epub
Enders Game 2 - Speaker for the Dead - Card_ Orson Scott.epub
Enders Game 3 - Xenocide - Orson Scott Card.epub
Enders Game 4 - Children of the Mind - Card_ Orson Scott.epub
Enders Game 5 - Ender's Shadow - Card_ Orson Scott.epub
Enders Game 6 - Shadow of the Hegemon - Card_ Orson Scott.epub
FREAKONOMICS_ A Rogue Economist Explores - Levitt_ Steven.epub
Fahrenheit 451 - Bradbury_ Ray.epub
Fear And Loathing In Las Vegas - Thompson_ Hunter S_.epub
Fight Club - Palahniuk_ Chuck.epub
Foundation 1 - Foundation - Asimov_ Isaac.epub
Foundation 2 - Foundation and Empire - Asimov_ Isaac.epub
Foundation 3 - Second Foundation - Asimov_ Isaac.epub
Frankenstein 1 - Prodigal Son - Koontz_ Dean.epub
Frankenstein 2 - City of Night - Koontz_ Dean.epub
Frankenstein 3 - Dead and Alive - Koontz_ Dean.epub
Guns, Germs and Steel - Diamond_ Jared.epub
HHGTTG 1 - Hitchhiker's Guide to the Gal - Adams_ Douglas.epub
HHGTTG 2 - The Restaurant at the End of - Adams_ Douglas.epub
HHGTTG 3 - Life, the Universe, and Every - Adams_ Douglas.epub
HHGTTG 4 - So Long, And Thanks For All t - Adams_ Douglas.epub
HHGTTG 5 - Mostly Harmless - Adams_ Douglas.epub
Harry Potter 1 - Harry Potter and the So - Rowling_ J.K_.epub
Harry Potter 2 - Harry Potter and The Ch - Rowling_ J.K_.epub
Harry Potter 3 - Harry Potter And The Pr - Rowling_ J.K_.epub
Harry Potter 4 - Harry Potter and The Go - Rowling_ J.K_.epub
Harry Potter 5 - Harry Potter and the Or - Rowling_ J.K_.epub
Harry Potter 6 - Harry Potter and the Ha - Rowling_ J.K_.epub
Harry Potter 7 - Harry Potter and the De - Rowling_ J.K_.epub
How to Make People Like You In 90 Second - Boothman_ Nicholas.epub
How to Talk to Anyone_ 92 Little Tricks - Driver_ Janine.epub
Jurassic Park - Chrichton_ Michael.epub
Lies My Teacher Told Me - Loewen_ James W_.epub
Lord Of The Flies - Golding_ William.epub
Molecular Mechanisms of Learning and Mem - Lee_ Frank.epub
Outliers_ The Story of Success - Gladwell_ Malcolm.epub
Rich Dad, Poor Dad - Kiyosaki_ Robert.epub
Seven Habits of Highly Effective People - Covey_ Stephen R_.epub
Slaughterhouse Five - Vonnegut_ Kurt.epub
Snow Crash - Stephenson_ Neal.epub
SuperFreakonomics - Levitt_ Steven.epub
Surely You're Joking, Mr. Feynman! - Feynman_ Richard.epub
The Alchemist - Coelho_ Paulo.epub
The Catcher in the Rye - Salinger_ J.D_.epub
The Elegant Universe - Greene_ Brian.epub
The Fountainhead - Rand_ Ayn.epub
The Giver - Lowry_ Lois.epub
The God Delusion - Dawkins_ Richard.epub
The Host - Meyer_ Stephenie.epub
The Iron Man - Howard_ Robert E_.epub
The Lord of the Rings 1 - The Fellowship - Tolkien_ J.R.R_.epub
The Lord of the Rings 2 - The Two Towers - Tolkien_ J.R.R_.epub
The Lord of the Rings 3 - The Return of - Tolkien_ J.R.R_.epub
The Lost Symbol - Brown_ Dan.epub
The Memory of Running - McLarty_ Ron.epub
The Minority Report - Dick_ Phillip.epub
The Mist - King_ Stephen.epub
The Physics of Star Trek - Krauss_ Lawrence.epub
The Power of Now - Tolle_ Eckhart.epub
The Selfish Gene - Dawkins_ Richard.epub
The Stand - King_ Stephen.epub
The Theory of Everything_ The Origin and - Hawking_ Stephen.epub
The Tipping Point_ How Little Things Can - Gladwell_ Malcolm.epub
Things Fall Apart - Achebe_ Chinua.epub
World War Z - Brooks_ Max.epub
Your Dream Home_ A Comprehensive Guide t - Smith_ Marguerite.epub
Zombie Survival Guide - Brooks_ Max.epub