Writing this one was torture. Once Ridley Scott came in, he wanted everything tailored to his style. I love the final result, plotholes and all. For more about the history, see Future Noir: The Making of Blade Runner by Paul M. Sammon.
Blade Runner (July 24, 1980) by Hampton Fancher
Blade Runner (Feb 23, 1981) by Hampton Fancher and David Peoples