Hunter S. Thompson stuff is lively, especially Fear and Loathing in Las Vegas.
Catch-22 by Heller is just a comic masterpiece about war. Maybe funniest book I've ever read.
O'Toole's Confederacy of Dunces is also a nice piece of humor/satire/commentary.
Depraved 'travel' books are nice... Kerouac's On The Road, and the darker Tropic of Capricon by Henry Miller.
I liked Kurzweil's Age of Spiritual Machines for its broad vision, and correct general ideas - even if the details are a little out of place.
Thoreau was a good kid.
Dostoyevsky is always excellent for drama on an epochal scale, especially books like The Idiot and The Brothers Karamazov.
I liked Turgenev's nihilistic Fathers and Sons a lot.
And some philosophy like Hobbes, Locke, Hume, Russell, and others can be very good. But extremely hard to decipher and then fully understand. But that can be true of many great books.
I need to read more, I haven't really read anything for a year or so
Damn school...