Looking for a classic book I could read to a very hyperactive nine year old.

My brother, nine years of age, is a very sweet little man. Sentimental, funny (or so he thinks) and exceedingly kind to those who are upset. But also, vulgar and prone to putting in his opinion on everything and everyone. What sort of classic book should the young man be smited with? Already trying Matilda, and he's just been insulting the parents for most of it, which is probably the right way to read the book. Any other ideas? Peter Pan looks exciting.