1 - Ubik
2 - The Three Stigmata of Palmer Eldritch
3 - Martian Time Slip
4 - A Maze of Death
5 - Divine Invasion (the 2nd of the VALIS trilogy)
6 - Eye in the Sky
Regarding movies influenced by his work:
The original "Blade Runner" movie is far better than "Do Androids Dream of Electric Sheep". The original "Total Recall" movie is far better than "We Can Remember It for You Wholesale". "The Terminator" is far better than "Second Variety". "The Truman Show" is better in some ways than "Time Out of Joint" (though this is a closer call, and as usual Dick's vision is a lot darker than Hollywood's take on it). "A Scanner Darkly" and "Minority Report" are also minor works, which you would lose nothing by skipping.
I would also avoid prety much all of his later work and his so-called "Exegisis". For me, Philip K Dick was best when he was writing straight scifi (or at least as straight as he could write it).
Later he tried to write more "literary fiction", or things that had little if any scifi in them, and failed utterly. His navel gazing and endless obsessing about a minor mystical experience in the Exegesis could also not be any more dull. Avoid.
Some of his early and mid-career work is fantastic, though. He is definitely one of my top three favorite scifi authors, if not the very top for his best work.
He wrote A LOT, however, mostly due to being incredibly poor and yet insisting on supporting himself and his family exclusively by publishing work that was appreciated by very few people throughout almost all of his lifetime. So overall his work is of very uneven quality, and can be very hit or miss if you insist on reading through much of it.
I can get why you prefer the movies, given that you write that you prefer PKD's "straight scifi", but to me his "straight scifi" is the most boring part of his output.
Do Androids Dream of Electric Sheep is not Blade Runner. Blade Runner is a single story-strand from Androids, re-imagined. It's a better movie for it, probably, but what makes PKD's stories to me is the density, with multiple intertwined stories.
As for Exegesis, it's for the specially interested. Of course it is navel gazing - it was his attempt at making sense of his mind after a psychotic breakdown. It was never written for publication.
Hugely influential to these types of works is Starmaker.
Here's a rough progression I recommend for those who want to delve into one of the best writers who has ever lived (of course hardcore PKD fans might disagree with the following, and I'd be happy to debate with them :-):
STARTING POINT:
- Ubik, Flow My Tears the Policeman Said, The Man In The High Castle, A Scanner Darkly, Do Androids Dream of Electric Sheep? - those are his most famous novels, self contained, and the most accessible. They're fantastic, and a great entry point into PKD's mind. Most of these are from the later years of his life, when he had developed a pretty consistent, high quality style. You just can't go wrong with these, and if you don't like them you probably shouldn't bother with the rest of his work.
- Movies based on his work, notably Blade Runner (which he himself expressed appreciation for, although he never saw it fully), and A Scanner Darkly, the first Total Recall + the adaptation of Confessions of a Crap Artist. While they're not strictly PKDian, they're a good way to get immersed in his way of thinking as the directors did a pretty good job of conveying his themes. The more recent ones (Adjustment Bureau, Total Recall remake, Minority Report, etc.) are fun as well but uneven in quality - but they can be a completely fine introduction to his mind bending ideas, especially if you want to convince friends who aren't into reading to try out his books.
INTERMEDIATE:
- Stuff from his mid-years: Galactic Pot Healer, Time Out Of Joint, Martian Time Slip, Confessions of a Crap Artist, The Crack In Space. Still very good stuff, but I think you need to be already well acquainted with PKD to fully appreciate them and see how his style and ideas were developing.
- The Valis Tri/Tetralogy (Valis/Divine Invasion/Radio Free Albemuth/The Transmigration of Timothy Archer). That's where you start to get deep into PKD lore, and you should read about his life to get the context in which they were written.
- Most of the short stories from ~1960 and onwards. Some are great, some less so, but they're short so you can easily get through the ones you like less.
FOR THE HARDCORE FAN ONLY:
- all the obscure short stories and remaining novels not mentioned above - they're not necessarily harder to get into, but they're from his earlier years and thus don't have the same level of craftsmanship (a few are not even really sci-fi). Also he wrote so much stuff that you should only spend time with those dozens of works if you're really, really into him.
- The Exegesis of PKD: a selection of about 10% of his personal notes, written towards the end of his life when he was completely {drugged out | schizophrenic | a religious nutjob} (pick one or more, or invent your own). It's basically his interpretations of life, the universe, and everything else, based on (somewhat sound) insights from philosophy, physics, biology, etc. This is an insane book that you can only appreciate (and have the strength to go through) if you already have a solid understanding of his world views and ideas.
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Someone recently wrote on reddit "Nobody writes like Feynman; but luckily he wrote a lot.", which is a quote that I love and would apply equally well to PKD.