PKD was more of a thinking mans sci-fi writer. While his books were very much sci-fi affairs, they seemed to be grounded in reality, with realistic characters. Also his novels were more than sci-fi. There are huge dollops of philosophy, sociology, politics and religion within a lot of writings as well.
I personally feel that his lesser works are more suited for film. They are, in some cases, nowhere near as deep, or involved as his better known novels. Though "Flow My Tears" and "UBIK" would be very enjoyable.