I gave this series the lowest rating possible. I have read a dozen of these stories myself, and they just have nothing to offer to my kids. The title character Junie is at best a bad mouthed, obnoxious brat whose behavior probably irritates most parent readers to the point that they would almost commit child abuse to stop her. From the kid readers' standpoint, it might be enjoyable to live vicariously through Junie, since she's completely unrestrained and never really gets punished for what she does. I can certainly see how some young children would find that very appealing, though others might be distressed if they empathize with Junie's classmates.
Before making this series part of your child's reading experience, I suggest that you think about whether your child tends to copy the characters or language from the stories that she reads. If the answer is yes, then save your family from years of therapy, and DO NOT BUY JUNIE B. JONES. Buy Beverly Cleary's Ramona books, Barbara Robinson's Best Christmas Pageant Ever, the Pippi Longstocking series, and even Curious George. These have naughty behavior, but they are much more balanced. If you are trying to wean your child from picture books, try Mary Pope Osborne's Magic Tree House series of chapter books.
Even if you don't think your child will copy Junie, first read a few pages yourself, so you know exactly what you are passing along. Do NOT select this for a gift unless you know that the child in question enjoys the series AND the parent/guardian does not mind.