I don't really recall when I first encountered Asimov.  I think it was right away with the Foundation trilogy (I know, there's more now) that I borrowed from the library, without even having heard of it.  Asimov wrote "good science-fiction" according to the librarian.  He sure did...

He didn't only write good stories, their foundation (pun intended (-;) was close to scientifically correct.  He even came up with some laws that are, as far as I know, considered as the basis (didn't dare to use "foundation" again) for artificial intelligence.  Ever heard of them?  They are:

(I'm not sure of the correct wording)

1. A robot is not allowed to harm a human, or allow a human to be harmed by his negligence.
2. A robot must execute the assignments given by humans, unless they conflict with the first law.
3. A robot must protect its own existence, unless this conflicts with the first or the second law.

They have evolved over time, and I've seen both "New laws of robotics", and an extension called the "zeroeth" law.  Asimov wrote quite some stories around these laws, and some "detectives in space".  None are any less than just "good", some (like the first three Foundation books) are simply excellent.  Don't expect any flashy surroundings or big action scenes, but do expect a very skilled narrator at work.