If you take the Foundation trilogy on its own, this is probably the best book. It really rounds off the series quite well in that sense - makes the other two fit a little better than they otherwise would have.

Perhaps not as dramatic as the second one - there's no massive defeat lurking or anything. Mostly it follows the same trend as the previous book, but now it's not the Mule hunting the second foundation, it's the first foundation. Perhaps my only gripe with this one is whilst we ultimately find out where the second foundation is, there are two places revealed as suspects at the climax, and whilst the characters may have been fooled - it was quite obvious that neither place could possibly be the true location.

All in all, a great end to the original trilogy. It will be exciting to see how the galaxy fairs in the final two books of the entire series.