Im my experience, Judy Blume's books are somewhat of a mixed bag. Easily the best of her books is the Fudge series. Actually, this is about the only series written by Judy Blume; most of her novels are one-offs. The Fudge series commences with Tales of a Fourth-Grade Nothing. Next comes Superfudge. (This was the book that introduced me to Judy Blume, if I recall rightly.) These have been followed more recently by Fudge-a-Mania and Double Fudge. All four books are narrated by Peter Hatcher, older brother of Farley Drexel Hatcher (aka Fudge) and baby Tootsie. Then there is Otherwise Known as Sheila the Great, which is narrated by Peter's nemesis Sheila Tubman. According to the Judy Blume official site, it is actually the direct sequel to Tales of a Fourth-Grade Nothing. So it's really the second book in the Fudge series.
These books are really enjoyable stories with plenty of humour, although Peter can be a bit whiney sometimes. I also learned a great deal about American culture from them, and the Sheila book introduced me to the concept of slumber parties (not that I ever had one; they're more a girl thing, I believe).
Another of Judy's finest works, IMO, is Blubber, which deals with school bullying and has a nice twist or two. Another book in my collection is Iggie's House, which tackles racism, although I didn't find it that memorable a story.
I don't have too many of Judy's more "grown-up" books, but one I do possess is Then Again, Maybe I Won't. Compared with the Fudge books and Blubber, it was pretty boring. However, this book did introduce me, at the tender age of 11, to, ahem, the phrase "wet dream". But even though it was described in fairly graphic detail, I actually didn't get it. I thought he'd simply wet his bed!
(When I finally did learn the "facts of life", including what a "wet dream" actually is, I looked on that passage with new eyes!)The only other Judy book I have, I think, is the non-fiction Letters to Judy, which was all a bit depressing. I never bothered with most of her other more grown-up books. But I would highly recommend her Fudge books and Blubber. When she gets it right, she can be a very enjoyable author indeed. However, her other more adult books struck me as kind of depressing just from their synopses, and of the Judy books I do have, Then Again, Maybe I Won't is my least favourite, even if it was enlightening after a fashion!
perhaps because by the time I got around to it I was older than 'fourth grade' (what we call third year primary here), and so it did not seem interesting. I enjoyed Blubber, Then Again Maybe I won't, Forever, and Just As Long As We're Together though .. those are the highlights but I think I've read them all.