“Over-rated? The foundation series? No way.”
There are other reasons to dislike the series:
http://www.theguardian.com/books/2012/dec/04/paul-krugman-asimov-economics
I have seen people here talking about only the first series and especially the first two books. I am one of those hating the series, but I admit that I read the first two books as a kid and found them very cool and started to read the rest as an adult and hated it. Stopped reading in the middle of the first prequel.
I never re-read the first two as an adult, but I suspect when reading as a kid I was just interested in space ships and laser guns. Reading the next ones as an adult I got angry at the books and what they preach and it became a chore as I didn’t enjoy them and just felt I have to finish what I started.
It just got this evil tone of “We are a small elite sentencing you to a life of torture and death now and because of the math we know that it is worth it in larger scale of things thousand years from now”.