One of the most celebrated works in science-fiction, this first part of a trilogy (or more depending how you see things) explores the notion of 'psycho-history' - the discipline that can mathematically predict large-scale future events - and how to accommodate or resist such happenings. In short, the galactic empire is crumbling and will descend into darkness for 30,000 years... unless the Foundation can act in certain ways through certain crises and make this decline last only 1000 years. I enjoyed thinking about events on such a large time scale but it Asimov wasn't too futuristic in some domains. Men still drank burbon and women were housewives or tertiary characters. Asimov created a world with galactic space travel, yet communication mediums and technology were pretty weak. Also, everything was 'atomic power', likely due to the book written in the early 50s, but still amusing.
Good stuff and I'll likely try the others.