Very dated, but all the more charming because of it.
My father read them to me with great expression when I was a child, and to this day, I can only hear or read them with his intonation (fortunately his was very good).
As with and compendium, there are some duffers, but the best are sublime: Matilda (obviously), Sarah Byng, John and many others.
For a modern and darker twist on these, see Tim Burton's "Melancholy Death of the Oyster Boy" (http://www.goodreads.com/review/show/638631854).