As a young squirt, I loved both his sci-fi (The Illustrated Man, surely one of the most original ways ever of unifying an anthology) and his child-friendly horror, like The October Country and The Hallowe'en Tree. In more recent times, I've found Zen in the Art of Writing a comfort and an inspiration.
Along with J. G. Ballard (RIP), he was an author I read more for his lucid, dreamlike prose than for the content (although that was pretty great too). His great skill was finding the magic in the ordinary; one of my favourite Bradbury stories, The Other Highway, is about a family who on a whim take the old, forgotten road instead of the interstate one evening. Another, The Sound of Summer Running, is about a kid who wants a new pair of trainers for the summer:
Somehow the people who made tennis shoes knew what boys needed and wanted, They put marshmallows and coiled springs in the soles and they wove the rest out of grasses bleached and fired in the wilderness. Somewhere deep in the soft loam of the shoes the thin hard sinews of the buck deer were hidden. The people that made the shoes must have watched a lot of winds blow the trees and a lot of rivers going down to the lakes. Whatever it was, it was in the shoes, and it was summer.
Douglas tried to get all this in words.
"Yes," said Father, "but what's wrong with last year's sneakers? Why can't you dig them out of the closet?"
He lived a long and I hope happy life, revered and loved.