I can see that POV. I just recalled some of the stories Heinline wrote and Dick’s story, “Hitchhiker’s Guide to the Galaxy” and thought they were somewhat similar.
Heinline wrote about people on other planets and other species that enjoyed killing humans and other entire species. So, I guess it really depends on what the OP means by “similar” when applied to both writers. However, I don’t dispute what you wrote. It seems entirely reasonable to me.
Peace Out!
You are probably thinking of Job: A Comedy of Justice, which kind of reminded me of Candide on acid.
If you are suggesting that Dick wrote that, you are mistake. The fifth book of the trilogy, Mostly Harmless (only written because of the unresolved problem with Agrajag) came out about a decade after Dick passed on. Hitchhiker was all comedy, I cannot think of any strict comedy written by PKD.
Dang! I was certain that Dick wrote Hitchhiker’s Guide. I am embarrased at being so wrong and I thank you for correcting me. I wonder what it was that Dick wrote that burned so strongly in my memory?
I know that he wrote: Blade Runner, Total Recall, Minority Report, Screamers and The Adjustment Bureau.
But he must have also written something else because he is definitely and seems to be permanently lodged in my memory for something famous - something else!
What can it be?
If you can link to an author, then you can spell the author’s name correctly. In any case, I agree with Amateur Barbarian; in a thread filled with bizarrely bad suggestions, Heinlein is perhaps the least appropriate.
Nobody is really much like Dick. Dick isn’t very much like Dick half the time. He published about a dozen more or less standard novels in the 1950s, none of which are very famous today for good reason. Then he wrote the brilliant The Man in the High Castle, which resembles nothing else of his. Then in the 60s he got really weird. I gave up after the one in which it was all somebody else’s dream.
If you want fatter books that have a flavor of conspiracies as well as the New Wave sensibility of the 60s, I’d suggest John Brunner. He also churned out endless crap until around 1965 with The Squares of the City, a stunning novel set in a city like Brasilia (the the real-world city of the future) plotted from a famous chess game. In 1968 his masterpiece Stand on Zanzibar appeared and it’s around 10,000 pages. He did a lot with environmental themes into the 1970s and he and Samuel R. Delany in Babel-17 were the leaders in forecasting cyberstuff.
Another Brit - for some reason, Dick, though totally American as a writer, reminds me of off-kilter Brits - who specialized in the creepiness of what media and modern society were doing to us is D. G. Compton. He’s another guy from the 60s and 70s heyday of the field and you can try pretty much anything of his from that period.
They both could write about 20 times better than Dick, though.
Maybe it was a lesser work of his, for the story that burns twice as bright burns half as long. There is a fairly substantial body of work from which to draw, including the short stories. Unless it was VALIS, you may have to go back and read through the bulk of it to figure out what it was. And it you do it all at once, you may need some therapy afterwards.
Charlie Wayne, please do some research before you answer a question. First, if you don’t know how to spell an author’s name, look it up. Second, once you’ve looked it up, be careful to use that spelling. Third, if there’s something written by a science fiction author that you want to remember, use the Internet Speculative Fiction Database, which lists everything they ever wrote. Fourth, if there’s a movie or a TV show based on the works of the author, look the author up in the Internet Movie Database, which lists every movie and TV show based on those works. Fifth, memorize the relevant URL’s:
http://www.isfdb.org/cgi-bin/index.cgi
Sixth, in this thread we’re naming authors similar to Dick. If you’re going to name such an author, it’s necessary to have read something by Dick. You listed “Blade Runner, Total Recall, Minority Report, Screamers and The Adjustment Bureau” as being by Dick. Those are the names of movies. They are based on Dick’s works, but some of those names are only the names of the movies, not of Dick’s writings. This suggests to me that you haven’t actually read anything by Dick.
Seventh, read the OP and follow it before you comment. The OP did not ask for people to list any science fiction authors they liked. They asked for people to name authors whose fiction resembled the fiction of Dick. Heinlein is not like Dick at all, and naming him doesn’t help.
I think of PKD as being obsessed with questions of identity and what it means to be human, as well as questions of truth and authority and how little they mix. His style is kind of breezy and quick and a little clunky.
Nick Harkaway, espeically in his novel The Gone-Away World, matches lots of these requirements, but not all of them. Style-wise, it’s breezy and quick, but not especially clunky; instead, it’s much more playful with language, self-consciously arch. The rest of it applies pretty well, though.
Job is a deliberate homage to Cabell and is very, very un-PKD. “They,” on the other hand, could have appeared as an early Dick story and no one would have questioned it.
However, the two stories are connected, across the decades. 
I think this is true for most values of Dick and Heinlein, but I still submit that Timothy Archer and Stranger come close to intersecting. Certainly, though, one can argue that those works are not representative of the canon of either of their respective authors.
A hearty second to the recommendation of William Browning Spencer.
In particular, I’d check out Zod Wallop, if you are after "… aspects of the distorted nature of reality, hallucinations, drugs and paranoia … " that are ALSO moving ruminations on the nature of humanity.
Vonnegut, there is some damn good Vonnegut that rivals PKD for strange. And, as I recall, his writing has a more artistic quality to it.