Foundation (Foundation Series #1)
Hard to review a classic, really. Especially one I read long ago, and have fond memories of. Suffice to say, although it shows that this was written as several short stories originally, it doesn't matter, in fact I wish a lot of modern authors would look at some of this older stuff and take note.
You can successfully world (or in this case, galaxy) build, without including pages and pages of description, in fact this is a pretty short book considering what it covers. That said, it can be a little expository for my taste in places, but that's part of the style of the day, and since it's not also weighted down with overly much descriptive text, it's not too bad.
As to the ideas, well perhaps the science doesn't hold up that well, and some of the western cultural/social mores of the time stand out a little too much now, and perhaps chaos theory scuttles the psychology+sociology writ large that is psychohistory, but it's still a good easy fast read. Which is the main thing, really.