Of all the Stratemeyer Syndicate series (which include The Hardy Boys and Nancy Drew), the Bobbsey Twins books are probably the most escapist. Nan and Bert are always twelve; Freddie and Flossie are always six. The family always lives in a big house, always has a good time, and always figures things out by the last page. They are, in short, the ideal nuclear family of the age-old American Dream variety, smiling in the land of plenty where no shadow can threaten unhappiness or want.
Because these books were intended for younger readers (about the range of the two sets of Bobbsey twins), they're pretty innocuous. Many of the books are simply accounts of childish adventures; others have a mystery element, but the mysteries are seldom dark or scary, almost never violent, and generally end in relieved laughter and hugs all around. Readers won't be confronted with major moral problems, the kids are well-behaved, and Mr. and Mrs. Bobbsey fill their traditional gender roles.
There are few at Exodus Books who haven't enjoyed the Bobbsey Twins books at some point in their lives. The whole series is full of harmless fun, easy reading, and lighthearted Americana. Two dangers: 1) this kind of happy-go-lucky escapism isn't sufficient to explain to kids what the real world is like, and 2) having your kids read an entire 72-volume series of books that won't challenge their reading ability probably isn't the best for their academic development.
Reading for pleasure doesn't need to be academically challenging all the time; we perfectly understand that, and agree that sometimes kids just need to read something fun and easy. The Bobbsey Twins books are perfect for this, especially since there's nothing inappropriate about them. At the same time, a steady diet without interruptions will likely leave them without a taste for really good literature, and without a desire to improve intellectually.
The first Bobbsey Twin book appeared in 1904, and is rumored to be the work of Edward Stratemeyer himself. In the beginning, the kids got older as the series progressed, but the writers realized the Twins were getting too old and locked them at the ages of twelve and six. This is a bit creepy if you think too hard about it, but kids don't care, and the Bobbsey Twins books are way better than TV for keeping children occuppied and entertained.