This one has been in my watch list for a long time. Admittedly, half the time I thought it was a film about vampire killers (Blade) and not Ridley Scott's neo-noir sci-fi.
I can see why the film has a cult following - it does the genre-mash so well and so vividly. The 80s electronica sound track is the best. The film also circles around the idea of the validity of human emotions and memories - can they still be real if you feel and remember things that aren't your own? The film was based on a perfectly titled short story, Do Androids Dream of Electric Sheep? by Philip K Dick. But ultimately, the film was a little...meh. I didn't learn much about Deckard except that he's little over his job of killing these androids named 'Replicants', but he does it anyway. No one really twists his arm and says he has to...or else. And really...he has nothing against the replicants.
Dick's many short stories were kind of like that too - imaginative and interesting worlds full of intricate detail about futures and dystopias, but when you take that away and all the paranoia and technological determinism, there's not much character or motive or story. People just did things because they do. Gondry wants to adapt Ubik, it'll be interesting to see how much depth he will add to it!
In summary - an 80s Fifth Element but less camp and more ambiguous angst.