I grew up on Tove Jansson's moomin books before the moomins were an industry. You may or may not have had the same experience, but few people realize that she didn't write just for children.
The book I recommend for everyone is her collection of short stories: Tales from Moominvalley. All of them are good and a few of them are excellent from a feminist point of view.
My favorite is "The Fillyjonk Who Believed In Disasters." It is a feminist story on one level, having to do with the duties that societies have traditionally assigned to women. On other levels it is a story of the way people are owned by the things they own, and even a story of the current oil disaster. Honest.
I also love "The Hemulen Who Loved Silence." For some odd reason I always see the Hemulens as Americans! And "The Invisible Child" is a very good story about abuse and what it does to people.