I just posted my Amazon review of the classic Do Androids Dream of Electric Sheep? I thought it was a pretty good book. Very different from the movie, but I thought it felt a tad dated, being 40 years old already.
I've always meant to get around to reading Do Androids Dream of Electric Sheep. I came across it again the other day, and decided now was the time. I haven't seen Blade Runner for many years, so I felt sufficiently distant from it to give the book an honest read.
The movie was a fair bit of a departure from the book, as many other people have noted. The androids of the book, other than Rachael, have only brief appearances. Roy Baty was much more exciting in the movie-- here, he is simply used to show the lack of empathy in androids and then quietly destroyed. Still, Dick did a very effective job of describing how similar to us the androids were, due to their high intelligence, yet still how alien (and dangerous) due to their lack of empathy.
The biggest difference between the movie and the book is the book's emphasis on the quasi-religion of Mercerism. Humans are able to use empathy boxes to share each others' emotions, and also those of the quasi-diety Wilbur Mercer. The androids, lacking empathy, are unable to participate in Mercerism, and seek to discredit and destroy it. I thought this was a great conflict based around the central theme of the book, but was confused by the actual physical manifestation of Mercer and what that was meant to imply. I also got the impression that Isidore was actually Mercer, or that might have just been the results of him fusing with the Mercer personality? That was a little strange.
Still, a good book, highly recommended. Complex enough that it probably deserves a second read.