Bob Magaw said:
Dangerous Days: The Making of Blade Runner
Probably the best making of film documentary I've ever seen (but I may be biased, as it is my favorite film, with Seven Samurai).
is this on Netflix?
yes, if you click on blade runner: the final cut, look for the bonus material disc (you can request separately, with or without the film proper)... that contains the doc dangerous days. it covers the challenging pre-production and complicated three-part financing history, the many script iterations, important differences with the seminal philip k. **** novel/source material - do androids dream of electric sheep, casting (early on dustin hoffman was the choice for deckard before widening creative differences led to harrison ford), futuristic conceptual design (syd mead was a working industrial designer), art and set decoration (when director scott was introduced to the art director, he said, "too bad for you, mate."), why budget constraints led to the signature retrofit architecture look, the actual shoot of course, which had many difficulties (night, rain, smoke - it actually saved money that would have otherwise been needed to dress up the back lot sets, a necessity given the budget constraints... after one shoot when scott broke out a cigar, a set hand asked if he had smoke in his home!

), cinematography, special effects (probably the last great analog, in camera, sci fi effects film, arguably unsurpassed by CGI to date), music, the troubled post-production (the completion bond financiers took the film away from scott and his editor briefly before another principal financier, alan ladd, jr and warner brothers insisted they be restored to the project), how disappointing tests and critical reaction led to several variants almost immediately and its anticlimactically quick demise on its intitial release, and how home video and other factors led to its rediscovery, resurrection and critical reappraisal as a contemporary masterpiece that transcends genre boundaries*, arguably the greatest sci film ever, to this day hugely influential (helped spawn the literary cyberpunk genre) and maybe the most eerily prescient film of its era (and not just about the look, feel and style of the future).
youtube has a version split into three parts (not how the original is), but is missing the first part, if you want a taste. BTW, the three disc 30th anniversary edition (25th had five discs, including two DVDs) with all the versions and the doc on blu-ray is about $15 at amazon?
http://www.youtube.com/watch?v=hFKpBsNEzfM
* la times film critic kenneth turan's (seen in the doc) '92 article below may have played some role in this rediscovery and reappraisal process...
Blade Runner 2 : The Screenwriter Wrote Eight Drafts--and Then Was Replaced. On His First Day, The Director Turned The Set Upside Down. Harrison Ford Was Never So Miserable. Years Later, Someone Stumbled Over The Long-lost Original. Nothing About This Cult Classic Was Ever Simple.
http://articles.latimes.com/1992-09-13/magazine/tm-1537_1_blade-runner-ridley-scott-orson-welles-othello
** i earlier got the basic blu-ray version of scott's prometheus, because i didn't have a 3-D player (and didn't intend to get one any time soon), but just decided to get the four disc special edition with unneeded 3-D disc, also now only about $15 at amazon, as it has a close to four hour making of doc absent on the basic edition... apparently not at netflix, and didn't see on youtube.