Too many. As a liberal I still find conservatives Kevin D. Williams (The Smallest Minority, Independant Thinking in the Era of the Mob) and James Rikards (Currency Wars, Aftermath, etc.) to be interesting and useful. Then there is Thomas Piketty (Capital in the 21st Century), Douglas Rushkoff (Throwing Rocks at the Google Bus).

Anyway, these few were enjoyably, but a warning: I have loaned books by the first two conservative authors to liberal friends and they didn’t like them, too far outside the bubble they like to live in. I like reading authors that have differing world views from myself.

EDIT: The Devil’s Chessboard is also a good read, but parts of it were disturbing to me.