Chandoraa: The
Blade Runner game is an awesome companion to both the film
and the book, mixing up elements from both of them in a really faithful, respectful way. It's only flaw, imho, is that its multiple possible endings make the plot suffer quite a bit. You really have to roleplay a lot within your head in order to fill the gaps. And you can really mess it up (or have a blast, if that's your thing) if you go around playing a schizoid McCoy that gets kitties down trees in one scene and kicks puppies in the next one). I don't think anyone would possibly be able to get all possible endings, especially since there's so much stuff that's randomized, but here's an LP that does a great job of explaining some of them, ripe with interesting trivia about the whole BR mythos, and with a nice amount of humor:
http://lparchive.org/Blade-Runner/.
Also, if you can manage (the game has no subtitles), play the original English version. The Spanish translation I had to deal with was... well, not good.