When I was a kid, I happened upon the first in 'The Foundation'. If a set of books could influence a mind, holy crap these certainly did. Soon after, read the 'Robot Series' (truth be told, under this vampire skin, it's all circuits and wires). Yeah this guy, to me, is the finest writer. I love lots of old and new sci-fi but this one.. in my opinion, is the master. I was also blown away that he continued series he wrote in the 50s.. later in the 80s. I was seriously bummed when he died. His words, though, might just make it 25,000 years into the future.