Phillip K. Dick. Do Androids Dream of Electric Sheep is his most popular. Otherwise known as [U]Blade Runner.[U]

He has a lot of good stuff. Dr. Bloodmoney, Clans of the Alphane Moon, Confessions of a Crap Artist, to name a few.

Started reading him in the 70's and he was publishing two decades before then. The really scary part is what was science fiction then is reality now.