The Essential Philip K. Dick
PKD is one of my favorite sci-fi writers and I recommend Ubik if you're a new reader, although like the article mentions, you definitely need to be in a certain mindset to "get it." The Man in the High Castle has an interesting concept but I don't think it's particularly well-written.One thing that I think goes unnoticed about PKD is how some of his earlier short stories are undeniably, unquestionably bad. Fair Game, for instance. He wrote it in 1953, a decade+ before his work started to get really good: The Three Stigmata of Palmer Eldritch was written in 1964, Do Androids Dream of Electric Sheep? in 1968, and Ubik in 1969.I personally find this a bit reassuring. It's nice to know that even someone as influential as PKD took a long time to develop.