I've had quite the interesting experience with Ray Bradbury's writings. Of course, the first book of his I picked up was Fahrenheit 451, and I did that just 6 or 7 years ago (I know, I don't know how I went so long before reading it). Maybe I'd feel differently now, but at the time, I was underwhelmed by the story. The writing was nothing special, and the plot was only mildly interesting, though this might have been because I've been spoiled on Star Trek and SG-1 since I was a teenager.
Jump to about 5 years ago, and I was reading a wonderful anthology of sci-fi stories, when I came across Bradbury's piece, "Mars is Heaven!" Instantly, I reevaluated what I thought about him. "Mars is Heaven!" is bizarre and utterly fascinating- the kind of story that I'm always looking for and hoping some day in some universe to write.